Accelerating Ground-Test Cycle Time: The Six-Minute Model Change and Other Visions for the 21st Century

15 Pages·1998·0.33 MB·English

by  Kegelman, Jerome T

AIAA-98-0142
ACCELERATING GROUND-TEST CYCLE TIME;
THE SIX-MINUTE MODEL CHANGE AND OTHER
VISIONS FOR THE 21ST CENTURY
Jerome T. Kegelman*
NASA Langley Research Center
Hampton, VA 23681
A bstract Cycle time reductions of up to two orders of
magnitude have resulted in corresponding reductions
The advantage of managing organizations to in inventories, work in process, labor costs, as well
minimize product development cycle time has been as facility overhead. Successes in the automotive
well established. This paper provides an overview and electronic industries, led by Japanese firms such
of the wind tunnel testing cycle time reduction as Toyota and Sony, provide ample evidence of the
activities at Langley Research Center (LaRC) and advantages of minimizing development cycle time
gives the status of several improvements in the to increase competitive advantage and decrease
wind tunnel productivity and cost reductions that costs.
have resulted from these activities. Processes have The aircraft manufacturing industry has been
been examined and optimized. Metric data from driven to follow suit with some success. However,
monitoring processes provides guidance for inherent in the development cycle of any new or
investments in advanced technologies. The most derivative aircraft are a series of wind tunnel test
promising technologies under implementation cycles. For consistency, the wind tunnel test cycle
today include the use of formally designed here is defined as the time between delivery of a set
experiments, a diverse array of quick disconnect of loft lines to a model designer and delivery of
technology and the judicious use of advanced wind tunnel test data. A typical new aircraft
electronic and information technologies. development will require several of these cycles,
each currently lasting as long as one year. A series
Introduction of these test cycles can contribute perhaps several
years to the development time of a new aircraft.
Over the past two decades, the manufacturing The wind tunnel test cycle includes the test
community in the United States has recognized that article or model design and fabrication time, the
a significant competitive advantage is gained by Model/Facility integration time, the wind tunnel
significantly reducing product development time. test time and the data reduction and delivery time.
As the time between product conception and its Substantial advances have been made in reducing
delivery to the market is reduced, the manufacturer(cid:213)s model design and fabrication time, notably led by
ability to respond and adapt to changing market the (cid:210)Six Day Model Team(cid:211) at the Boeing
demand is increased, while the costs of doing Commercial Aircraft Group.
business decrease substantially. The advantages of The wind tunnel testing community has just
rapid product development cycle time for adapting recently begun to focus on substantially reducing
to a niche market or responding to changing the cycle time associated with wind tunnel testing.
consumer demand ahead of the competition are It can hardly be any advantage for a customer to
obvious. The cost savings of rapid product provide a test article in six days if the nearest
development far outweigh the additional cost for tunnel availability date for a high Reynolds number
developing the infrastructure, processes and facility is eight to ten months down the road!
machinery. Recent efforts at NASA Langley Research Center
____________________________ to reduce wind tunnel testing cycle time have been
*Head, Research Facilities Branch, Aero- and Gas- initiated. A few recent successes, along with plans
Dynamics Division, Member AIAA.
for continued cycle time reduction, are the subject
Copyright ' by the American Institute of Aeronautics and of this paper.
Astronautics, Inc. No copyright is asserted in the United States under
Title 17, U. S. Code. The U. S. Government has a royalty-free license
to exercise all rights under the copyright claimed herein for
Government Purposes. All other rights are reserved by the copyright
owner.
1
American Institute of Aeronautics and Astronautics
AIAA-98-0142
B ackground and History installation in the test section until the model is
removed from the test section, less Scheduled and
About four years ago, as a result of a major re- Unscheduled Downtime. (Appendix A includes a
organization of the NASA Langley Research more complete list of the definitions of the LaRC
Center, significant changes began in the way wind metrics.) These data represent non-weighted
tunnels were operated at the Center. The averages for the National Transonic Facility, the
consolidation of wind tunnel operations in the Unitary Plan Wind Tunnel, the 16-Foot Transonic
Aero- and Gas-Dynamics Division (formerly the Tunnel, and the 14- by 22-Foot Subsonic Tunnel.
Aerodynamics Division) under one operations Productivity has increased by a factor of 3 since
branch was undertaken to initiate a major cultural 1994, while the cost per polar has decreased by
change.1 In particular this change was undertaken to nearly 60%. These improvements have been made
improve customer satisfaction with wind tunnel while the customer satisfaction index has increased
operations and data quality. In addition, it was also from just over 3.5 to nearly 4.5, using a scale from
believed that a centralized management of the 1 to 5.
tunnels could provide more emphasis on
commitment to schedule, attention to data quality, T he Changing Paradigm
improvements to productivity, and improvements
to reliability of these facilities. By combining the For as long as anyone in the business today
operation of these facilities under one organization, can remember, the mode of operation for wind
improvements across all facilities could be tunnel testing has been for the providers of wind
accomplished by standardization and use of tunnel services to sell wind tunnel time and not
common tools and test techniques. Langley has wind tunnel results. The dilemma associated with
also formed what is called the Wind Tunnel selling wind tunnel time and not wind tunnel data,
Enterprise (WTE), a virtual organization which while measuring performance by counting data
includes the providers, the customers and the points, is illustrated in Figures 2 through 5.
stakeholders for the wind tunnel activities at the Figure 2 shows that the wind-on run hours has
center. increased by a factor of 2.3 in the 16-Foot
Following the reorganization, a set of goals Transonic Tunnel since 1994. Figure 3 shows that
were developed for the Research Facilities Branch the tunnel productivity as measured by the number
(RFB), the organization responsible for the of data points, has gone up by a factor of 5.1.
operations of most of the major facilities at LaRC.2 Shown in Figure 4 are the number of tests per year
These goals were: from the years 1983-1997. In 1997, the tunnel
- Be customer driven, meeting negotiated produced over 5 times the data produced in 1994
customer expectations 100% of the time. (figure 5). Note that the number of tests per year
- Provide customers with data at required shows no significant increase between the years
uncertainty level (no better/no worse). 1994 and 1997, certainly not commensurate with
- Operate based on sound business practices. the dramatic increases in productivity achieved in
- Provide (cid:210)world class(cid:211) basic instrumentation 1997. Clearly a great deal more data per test is
set. being generated, yet no more tests per unit time are
- Continuously improve test process. being completed. These results hold true for all of
- Provide data in a timely manner that fits Langley(cid:213)s major wind tunnel facilities.
customer development cycle. To move beyond this level of performance and
- Continuously improve productivity and reduce shorten the duration of each test (or increase the
cost of operating facilities. number of tests), the paradigm of selling tunnel
time and not tunnel results must change. Several
The substantial effort focused on achieving promising technologies for changing this paradigm
these goals has had an enormous impact on the and substantially decreasing the test cycle time will
productivity of the facilities. Figure 1 illustrates be addressed in section IV.
the positive effect this effort has had on
productivity, as measured by Polars per User C ycle Time Reduction as a Goal within NASA
Occupancy Hour, Cost per Polar, and Customer
Satisfaction. User Occupancy Hours (UOH) are It has been well established that the best
defined as the time from the start of model practice for changing an organization to one where
2
American Institute of Aeronautics and Astronautics
AIAA-98-0142
minimizing cycle time is of the highest priority is along with developing a credible and defensible
to ensure that all levels of the organization support Data Quality Assurance Program and unparalleled
this objective.3 It is clear that NASA, as an customer satisfaction. A mission statement,
agency, has endorsed reducing aircraft development measures of performance, and goals were
cycle time from the top levels at Headquarters down developed. The mission of the WTE is to:
through the facilities responsible for tunnel (cid:210)Provide reliable, accurate research
operations at the individual Aeronautics Centers. information to the aeronautical community in a
In the Agency(cid:213)s Strategic Plan3 there are four timely manner. To accomplish this requires a
strategic enterprises, one of which is the focus on increasing productivity, cost effective
Aeronautics and Space Transportation Enterprise. operations, technical support that adds value, and
This enterprise has three major technology goals the development of new facility capability and test
supported by ten enabling technology objectives. techniques.(cid:211)
The second of these three goals is called
(cid:212)Revolutionary Technology Leaps(cid:211) and is defined In recognition of the dilemma noted above,
as: where productivity has been quantified in terms of
(cid:210)Revolutionize air travel and the way in which data acquisition rate, with high data volume as the
aircraft are designed, built and operated.(cid:211) goal and not results, the goals of the WTE have
been re-examined. The initial set of goals was:
Under this goal the enabling technology - Accuracy - Better than 0.0001 in drag
objective is: coefficient
(cid:210)To provide next generation design tools and - Timeliness - Final data the same day
experimental aircraft to increase design confidence, - Cost Effectiveness - 30% decrease
and cut the design cycle time for aircraft in half.(cid:211) - Value added support - customer confidence
- Reliability - 100 percent achievement of
The Agency has established the Wind Tunnel schedule commitments
Facility Group Director(cid:213)s Office (WTFGDO) which - Productivity - 600 percent increase in
is responsible for the coordinated and efficient Polars/hour
operations of the Agency(cid:213)s wind tunnel facilities in
support of its programs. The WTFGDO has While the outcome of the activities of the
strongly endorsed a six-fold reduction in the wind WTE focused on meeting these goals has been to
tunnel test cycle time in order to help meet the accelerate the accomplishment of this set of goals,
overall reduction of aircraft development by a factor test cycle time has not been reduced in proportion
of two. The WTFGDO has sponsored two multi- to the increases in productivity. In July of 1997,
day workshops on cycle time reduction involving the WTE revisited these goals and developed a more
the organizations responsible for the Agency(cid:213)s comprehensive set of goals, consistent with the
major wind tunnel operations at Ames Research Agency(cid:213)s Strategic Plan. The complete set of
Center, Lewis Research Center, and Langley revised goals are included in the Appendix A. The
Research Center. Also included were the operators technical goals addressing cycle time reduction are:
of the major wind tunnel facilities at the Air Force
Material Command(cid:213)s Arnold Engineering Technical Goals
Development Center. This group, representing all By 2002, the WTE provides world class
of the nation(cid:213)s large wind tunnel facilities, has subsonic, transonic, and supersonic test capability
developed consensus agreement on aggressive goals in support of NASA’s goals for Global Civil
for reducing the time to conduct wind tunnel tests. Aviation, Access to Space, and Revolutionary
A significant outcome of these workshops is the Technology Leaps.
common recognition that all suppliers of wind By 2000, the WTE provides fast, low cost,
tunnel services are actively pursuing similar cycle concept screening test capability across the Mach
time reduction goals, and opportunities exist for range (0<M<20) to support the development of the
leveraging technologies developed at these various next generation commercial and military aircraft and
sites for the benefit of all. space launch vehicles.
The Wind Tunnel Enterprise at Langley The WTE fully integrates advanced wind tunnel
Research Center has now placed wind tunnel test testing into the next generation aircraft design
cycle time reduction as one of its highest priorities, processes by providing:
3
American Institute of Aeronautics and Astronautics
AIAA-98-0142
- an order of magnitude reduction in complete was found that the test project engineer had to enter
wind tunnel test cycle time by 2002 and two the wing pressure tap position as many as 5 times
orders of magnitude reduction by 2010 in various formats during the preparation for a test
- virtual participation by test team for entire plan. Now all information is entered only once,
test cycle with provisions for corrections. The infrastructure
has been put in place to allow the test plan to be
The benefits of undertaking a systematic, broad iterated between the customer and the test engineer,
and multi-disciplinary approach to cycle time remotely and asynchronously.
reduction has been well established throughout the The test plan management system provides the
manufacturing industries.4,5 The effort should tunnel operators with significantly enhanced access
permeate all layers of management from the shop to all information needed to efficiently conduct
floor to the Division Offices responsible for tunnel wind tunnel tests. The test plan management
operations. Fortunately, sound methodologies have system will also provide the customer with (cid:210)real
been established for reducing cycle time, which will time(cid:211) access to all information about the test and
not be repeated here. A brief outline of what has the research results from the test.
been done and what is planned follows: The processes have been examined for the
model design and fabrication, and efforts are now
I: Establish and Understand the Process underway to extend the test plan management
system to cover the model planning process as
A small team was formed in 1996 to study and well. It should be noted that there are other related
clarify the test process in use at LaRC. This team processes that accompany a test such as financial
has developed a detailed structure for the testing and business processes for funding a test, as well as
process for the Aero- and Gas-Dynamics Division the procurement and contract processes for
wind tunnels. This process, illustrated in figure 6, supporting tests. While much less has been done
accounts for all activities in the testing process for these processes, efforts are underway to
from initial request for test time by the customer to streamline all processes associated with wind tunnel
delivery of the final data and test close-out.2 Each testing.
step of the process is being examined to reduce
time, to reduce resource requirements, and to II: Measure Each Step
improve customer satisfaction. For example, all
facilities now use an electronic, web-based test Measures of performance and goals were
request process, a standard test plan format, and developed to determine progress towards
standardized pre-test and post-test meeting accomplishment of the mission of the WTE. To
agendas. Standard procedures have been developed monitor these metrics required that each facility put
for most routine test activities, including assembly in place a system to gather the data. Prior to the
and verification of joints involving tapers and keys, formation of the RFB, this data gathering was
set up and use of the Balance Dynamic Display sporadic at best, except in the National Transonic
Units used in all facilities, and calibration and Facility, where detailed data on facility
installation of accelerometer type model attitude productivity, downtime, etc. has been kept since
measurement systems. the facility first came on line.2 Since the formation
The examination of the required documentation of the RFB and the initiation of the WTE, all
of the test process has led to substantial facilities are routinely gathering productivity data.
streamlining efforts, which includes the recent When fully configured, the test planning
introduction of an automated test plan management management system will track the following
system. This system serves to keep all members measures of performance:
of the test team up to date and involved in the
plan(cid:213)s development. It tracks relevant information 1. Operational hours
in databases, tracks and provides automatic 2. Data per occupancy hour
notification of due dates and action items and 3. Cost per data unit
provides automatic setup and tracking of the test 4. Maintenance cost
execution at the tunnel. This system eliminates 5. Data accuracy, quality, and uncertainty
the need for anyone in the test planning process to 6. Plan to actual
enter information more than once. For example, it 7. Workforce per facility
4
American Institute of Aeronautics and Astronautics
AIAA-98-0142
8. Time to deliver data IV. Focus on the Bottle Necks
9. Facility downtime
10. Model installation time It has proved beneficial to have Multi-
Disciplinary Working Groups study the test
Data tracked in this manner provide key insight planning and the model design and fabrication
as to where we stand to gain the greatest process. Teams are now being formed to address all
improvements in test cycle time. Figure 7 remaining processes associated with tunnel testing.
illustrates how the activity at a wind tunnel is Each team is to include membership from all
typically proportioned. The major learning from disciplines affected by the process, such as tunnel
these data is that nearly 50% of the activity at a technicians, test engineers, management,
facility is spent on the test article, either with procurement and those responsible for resource
model installation or with the configuration allocation.
changes. The tunnel actually runs only 25 - 30% A substantial focus of this re-engineering effort
of the time! This eye-opening realization has led to is to identify barriers to accomplishing tasks in the
the focus on very rapid model changes; i.e., 6- shortest possible time. These bottlenecks may be
minute model changes. The author had set the goal facility hardware related, or there may be procedural,
of 6 minutes before learning of the industry organizational or cultural barriers that are hindering
standard practice for large facility utilization. The the accomplishment of the desired goals. The task
notion of a 6-minute model change is often met at hand is to identify and eliminate them one by
with disbelief, especially where configuration one. Three of the more promising areas of focus
changes can now take an entire shift and complete are addressed below.
model installations can take as much as a week.
As difficult as it is for wind tunnel veterans to U se Formally Designed Experiments
accept the notion of a 6-minute model change,
industry-wide (cid:212)best practices(cid:213) would suggest any The Langley Research Center wind tunnel
major machinery changeover should take less than community is considering formally designed
60 seconds!4 experiments as an alternative to the high-volume
data collection strategy currently followed by the
III. Educate and Train aerospace community at the LaRC tunnels and
elsewhere.6 As mentioned above, productivity has
The WTE has developed a set of cultural goals been traditionally quantified at most major wind
which address a critical element in any cycle time tunnel facilities in terms of data acquisition rate,
management plan. The goal is : with high data volume as the goal. However, since
By 1998, the WTE creates a culture of tunnel schedules are extraordinarily full, with lead
excellence in wind tunnel technology and times of up to two years, it is a natural tendency
operations through creation of a "university" type for the wind tunnel customer to have a long list of
environment which: test conditions in hand upon arrival. Customers are
trains all workers in order to driven to use a strategy of acquiring not only the
- sustain and grow all wind tunnel skills highest priority data, but also lower priority data
- provide repository of all our wind tunnel since the next testing opportunity may well be two
knowledge years away! Since the prevailing wisdom has been
- continually develop all technical staff skills to sell tunnel time by 8-hour shifts, the customer
will use every shift allotted for each test, regardless
conducts research/development of of the amount of data collected. Furthermore, the
- test technology final results of many tests often rely on only a
- new testing capability subset of the data acquired in a given test,
suggesting that certain efficiencies can be realized
A curriculum including the basic principles of by a more rigorous pre-test focus on the specific
cycle time management, based primarily on the objectives and the resources required to achieve
methods found in references 4 and 5, will be offered them.
to all WTE participants. All facility managers and Designed experiments seek to identify in pre-
supporting supervisors will be trained in these test planning those specific questions that are to be
methods. answered by the wind tunnel test, and then to
5
American Institute of Aeronautics and Astronautics
AIAA-98-0142
quantify the minimum resources required to answer figure 8. While wind-on minutes comprise only a
those questions. This consistently leads to smaller portion of the entire test cycle and these results
resource requirements than in current tunnel testing reflect only a limited number of trial cases, formal
procedures. methods of experiment design appear to have the
Extreme care must be given to the formulation potential for significant resource savings in wind
of the test objective, so that the end of the test is tunnel testing.
not determined by the expiration of test time, as
has been our tradition, but by the accomplishment E liminate Time Consuming Tasks
of a quantified set of results! While a test objective
is always given in each and every test plan at Pre-test investment in technology and
LaRC, these are not always developed to processes that substantially reduce the configuration
quantitatively indicate what is to be accomplished. change time (recall figure 7) can help achieve the
A typical objective statement today might read as goal of accomplishing the test in minimum time.
follows: The notion of using quick disconnects and standard
interfaces in tunnel testing has been around for
Perform high speed force and moment testing decades. However, in the past, minimizing cycle
on configuration XYZ to examine stability and time was not as high a focus as it is today, and
control characteristics. facilities have become accustomed to conducting
business using the same methods that have been
Whereas a more appropriate objective used for years. The bundle of very fine wires
statement would be as follows: attached to strain gauge balances which must be
fished through the sting and out of the tunnel with
Develop an analytical model of the stability each balance change serves as an example of using
axis coefficients of roll moment and yaw moment methodology from the 1950(cid:213)s in tunnels today!
for configuration XYZ as a function of angle of LaRC has switched most of its balance inventory
attack from -4(cid:176) to +20(cid:176) and side slip from -8(cid:176) to over to using a small standard connector attached to
+8(cid:176) at a constant Reynolds number per foot of the balance to eliminate this problem.
4x106 and at Mach Numbers of 2.4 and 2.7 LaRC is currently developing a standard
Ensure that there will be a probability of at model/balance/sting interface hardware for use in
least 90% of resolving a change in roll as small as the Unitary Plan Wind Tunnel, the 16-Foot
–0.0001 and yaw of –0.0002. Transonic Tunnel, and the Low Turbulence
There will be at least a 95% probability that Pressure Tunnel, which often run the same model
the coefficients predicted by these models will not through each facility to cover a wide Mach number
differ from the true population means by more than range. While this project is in its infancy, it is
these amounts. similar to and will be coordinated with an effort at
Ames Research Center, to avoid a duplication of
Unless the test objective is defined with effort and hopefully extend the number of facilities
sufficient detail, accompanied by the level of using common interfaces.
confidence required for the results, the completion While the idea of quick disconnects is not
of the test is not defined. unique to LaRC facilities, each facility presents a
Four designed experiments were conducted in unique set of challenges with respect to rapid model
LaRC wind tunnels in 1997, each time comparing changes, and cryogenic tunnel testing can be one of
results with those obtained using conventional the most challenging.
methods. The same or better technical results were In anticipation of a series of tests planned for
achieved with a total of over 80% fewer data points BCAG on the W50, MD-11, and MD-XX last year,
in tests at the Unitary Plan Wind Tunnel, the 16- it was deemed advantageous to minimize the
Foot Transonic Tunnel, and 14- by 22-Foot amount of time spent changing over wings from
Subsonic Tunnel, on various wing-body-tail the W50 to the MD-11. Each wing had several
configurations and an X-33 single-stage-to-orbit hundred pressure taps which had to be connected to
technology demonstrator model. In these tests the Electronically Scanned Pressure (ESP) units
there were corresponding reductions in required with each wing change. In addition, a second W50
wind-on minutes and associated costs of configuration was to be done without the wing
consumables. The average savings are illustrated in pressures included for a force and moment test.
6
American Institute of Aeronautics and Astronautics
AIAA-98-0142
A set of quick disconnects (see figure 9) and implement the most likely and beneficial
suitable for cryogenic use were designed with a instrumentation technologies that will provide a
Grafoil seal, as opposed to Neoprene, that are found radical improvement in model installation cycle
in commercially available disconnects. The time. It requires the design and fabrication of a
principal challenge was to be able to seal under prototype model with an on-board integral
cryogenic conditions, whereas the commercially instrumentation system, which allows for both
available disconnect design tested unsuccessfully conventional and advanced micro-electro-mechanical
cryogenically. These disconnects were also (MEMS) sensors. This (cid:210)plug and play(cid:211) model will
designed with the 48 port configuration to match include an Application Specific Integrated Circuit
the ESP modules. The quick disconnects were also (ASIC) based data system and wireless or fiber
to be used with blanking caps used to "plug" the optic data transmission system, thus eliminating
pressure tubes for force and moment tests. all instrumentation hook-up in the tunnel.
A total of 5 shifts were estimated to complete A block diagram of the system under
the hook-up the "old way" but the wing change was development is shown in figure 10. The scope of
accomplished in 3 shifts using the quick the project includes the integration of MEMS type
disconnects. The actual time saved was about 2 sensors and ASIC interfacing circuits into the wind
shifts, representing a 40% reduction on the first go- tunnel model during design and fabrication.
around with these designs. This change included Development is underway for in-model data system
filling and sanding the model to be ready for test. electronic circuits using ASIC technology and a
The first attempt was not without some difficulties virtual wire data transfer system that will transfer a
with the disconnects; notably, it was troublesome composite data stream from the wind tunnel model
tracking specific tubes which had come loose instrumentation system to the control room data
because of the tubing having limited flexibility acquisition system. University and industry
while it was constrained in the connector. Also, partners are involved in this program. The plan is
the choice of a random hook-up caused some to minimize, or eliminate, most if not all of the
problems in the beginning which, in the future, instrumentation cabling between the model and the
will be considerably improved. The "plugging" of sting, allowing very rapid model installations.
the tubes was accomplished literally in minutes, Accomplishments over the last year include a
rather than a half a shift to a shift. This activity preliminary review of candidate commercially
illustrates a cycle time reduction of over two orders available hardware technology for the Telemetry
of magnitude. Systems using Radio Frequency (RF), Infrared (IR),
In the future, it is planned to use this design or Fiber Optics, and Ethernet communications
an alternate for the ESP’s in the tunnel(cid:213)s wall technology. To evaluate the technology in the
pressure system to ease the replacement of modules field, tests were conducted in the 16-Foot Transonic
and for future wings such as the Boeing 777 model Tunnel (see figure 11). Results for this evaluation,
to be tested in FY98. The customer deemed the shown in figure 12, indicate Fiber optics and 100
connectors successful and would recommend them BT Ethernet meet the required data rate of 25
for any similar test program like the W50/MD-11 mbits/sec. RF and IR are applicable to meet data
with a common fuselage configuration. The patent rates lower than 1 and 10 mbits/sec, respectively.
for the design is being reviewed by a commercial The RF data rate was found to be 0.65 mbits/sec,
vendor; however, the Cryogenic application is while the IR data rate and 10BT data rate were
unique to the few cryogenic tunnels in the world, found to be 8.5 and 8.6 mbits/sec, respectively.
making it difficult to justify its commercial value. The definition of the on-board data system
A substantial effort was initiated in 1996 to requirements for force balance, AOA, pressure
revolutionize the model instrumentation hardware sensors, and shear stress sensors was completed this
for typical wind tunnel tests. Advances in the year, including electronic modules for the Sensor/
electronics industry over the last decade allow Driver, Data System, and Controller Systems. The
miniaturized electronic systems to be customized design of a Printed Circuit Board (PCB) version for
for specific applications at relatively low cost. An the on-board system is in progress. The Center has
effort is in progress to evaluate and implement, for established an electronic circuits design automation
wind tunnel use, such technology that is now capability to develop cost effective application
commonplace in such devices as credit-card sized specific integrated circuits.
digital cell phones. The objectives are to identify
7
American Institute of Aeronautics and Astronautics
AIAA-98-0142
C losing Remarks Ground Testing Technology Conference, New
Orleans, LA, June 17-20, 1996.
The NASA Langley Research Center is 3NASA Policy Directive (NPD)-1000.1
continuing an aggressive program to re-engineer the (cid:210)NASA Strategic Plan, 1998,(cid:211) Available through
way wind tunnel testing is accomplished. NASA Headquarters, 300 E Street, S.W.,
Reduction of test cycle time has been elevated to Washington DC 20546 Also available at:
the highest priority, with the goal of radically http://www.hq.nasa.gov/office/nsp/NSPTOC.html
accelerating the test cycle. A comprehensive 4Northey, Patrick and Southway, Nigel, (cid:210)Cycle
approach to cycle time reduction is being Time Management: The Fast Track to Time-Based
systematically carried out, in which every aspect of Productivity Improvement,(cid:211) Productivity Press,
the test process is being driven towards minimizing May, 1994.
the time for each step. Metrics are being 5Goldratt, Eliyahu M. and Cox, Jeff, (cid:210)The
continuously acquired which serve to guide the Goal: A Process of Ongoing Improvement,(cid:211) North
investments in process improvements as well as River Press, Aug, 1994.
evaluate progress. The most promising 6DeLoach, Richard, (cid:210)Applications of Modern
technologies under implementation today include Experimental Design to Wind Tunnel Testing at
the use of formally designed experiments, a diverse NASA Langley Research Center,(cid:211) AIAA Paper No.
array of quick disconnect technology and the 98-0713, 36th Aerospace Sciences Meeting and
judicious use of advanced electronic and information Exhibit, Reno, NV, Jan 12-15, 1998.
technologies.
The new goals for the LaRC Wind Tunnel Appendix A: Metric Definitions
Enterprise will provide focused direction for
tomorrow, while the momentum being developed The metrics used in the Wind Tunnel
today gives promise that they will be met and Enterprise at LaRC are defined as follows:
exceeded in the foreseeable future. Total Occupancy Hours (TOH) = (Hours
facility is open each day) x (52 weeks x 5
A cknowledgment s days/week) - Holidays
Available Occupancy Hours (AOH) = TOH -
This paper should be considered a report on the (Scheduled Downtime)
efforts of many individuals at LaRC, although where Scheduled-Downtime includes, for
responsibility for any inaccuracies in the example, time for annual maintenance, facility
presentation is mine alone. I especially want to upgrades, routine scheduled tunnel checks, etc.
acknowledge the essential contributions of Dr. User Occupancy Hours (UOH) = (Time from
Richard DeLoach, Dr. Seun Kahng, Mr. William start of model installation in test section until
Tomek, Mr. Daniel Cler, and Mr. Elwood Putnam. model removed from test section) - (Scheduled
I also want to acknowledge the contributions of the Downtime) - (Unscheduled Downtime)
LaRC Navigation Center and RFB staff, and the where Unscheduled Downtime includes
staff of the many other organizations at LaRC time lost because of tunnel failures, data-system
supporting the Aero- and Gas-Dynamics Division failures, power delays, etc.
and the wind tunnel re-engineering effort. Polar = 15 data points.
R eferences Appendix B: Revised WTE Goals
1Putnam, Lawrence E., (cid:210)Re-Engineering Wind T echnical Goals
Tunnel Testing at NASA Langley Research By 2002, the WTE provides world class
Center,(cid:211) Symposium of the International Test and subsonic, transonic, and supersonic test capability
Evaluation Association, Huntsville, AL, October in support of NASA’s goals for Global Civil
2-5, 1995. Aviation, Access to Space, and Revolutionary
2Putnam, Lawrence E., (cid:210)Wind Tunnel Technology Leaps.
Productivity Status and Improvement Activities at By 2000, the WTE provides fast, low cost,
NASA Langley Research Center,(cid:211) AIAA Paper No. concept screening test capability across the Mach
96-2260, 19th AIAA Advanced Measurement and range (0<M<20) to support the development of the
8
American Institute of Aeronautics and Astronautics
AIAA-98-0142
next generation commercial and military aircraft and M anagement Goals
space launch vehicles. The WTE management demonstrates the
The WTE fully integrates advanced wind tunnel importance of staff through making the WTE a
testing into the next generation aircraft design desirable place to work by defining and
processes by providing: implementing realistic work expectations by April,
- an order of magnitude reduction in complete 1998, and a true dual-career ladder for all WTE staff
wind tunnel test cycle time by 2002 and two by September, 1998.
orders of magnitude reduction by 2010 The WTE management demonstrates
- virtual participation by test team for entire commitment to achieving the WTE goals by April,
test cycle 1998, through
- alignment of resources with goals
O perations Goals - teaching the new way of working
The WTE meets all commitments to programs - communicating and documenting the
and customers’ expectations in a timely manner message of the WTE
while maintaining technical and operational
excellence through continuous improvement of ISO The WTE encourages and participates in
9001 certified processes in the areas of alliances with other wind tunnel service providers
- state of the art test techniques to furnish the United States with the world’s finest
- efficient test processes wind tunnel services.
- reliability centered maintenance
- value added attitude
C ultural Goals
By 1998, the WTE embraces business like
practices and takes pride in providing world class
testing services to its customers by
- promoting awareness of faster, better,
cheaper means of providing wind tunnel
services
- making the customer a welcome part of the
WTE and exceeding all his expectations
- making the total experience of the customer
enjoyable and intellectually stimulating
By 1998, the WTE creates a culture of
excellence in wind tunnel technology and
operations through creation of a "university" type
environment which
trains all workers in order to
- sustain and grow all wind tunnel skills
- provide repository of all our wind tunnel
knowledge
- continually develop all technical staff skills
conducts research/development of
- test technology
- new testing capability
9
American Institute of Aeronautics and Astronautics
AIAA-98-0142
Metrics for Major Facilities at LaRC
Non-weighted Averages for NTF, 16 Foot, 14 x 22, UPWT
4 5
3.5
4
199UOH) 3 4.5 Cus
since Polars/ 2.5 Customer Satisfaction tomer
nt nd 2 4 S
ea a
vemolar 1.5 Polars/UOH tisfa
oP c
mprCost/ 1 3.5 tion
I(
Cost/Polar
0.5
0 3
1994 1995 1996 1997
FY
Figure 1. Productivity, Cost and Customer Satisfaction Metrics for LaRC Facilities
800
700
s
r
u
o
H 600
n
u
R
of
r
e 500
b
m
u
N
400
300
94 95 96 97
Year
Figure 2. Number of Run Hours per Year for the 16-Foot Transonic Tunnel
10
American Institute of Aeronautics and Astronautics