NASA Technical Reports Server (NTRS) 20140002367: Robust, Optimal Subsonic Airfoil Shapes

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by  NASA Technical Reports Server (NTRS)

capture variations in relay asset interac- culated based on the soil types con- mission, and has not been able to influ-
tions, Earth/Mars time phasing, and sea- tained in the given scenario. Next, the ence mission design. Further, the notion
sonal variations in holidays). This model scenario contains a description of what of moving to sustainable operations dur-
is used to estimate the ops efficiency fac- sequence of operations configurations is ing Prime Mission — and the effect that
tor for each operations configuration. used, for how many days each, and this is that move would have on surface mis-
The second model in a separate Excel used with the corresponding ops effi- sion productivity and mission objective
spreadsheet is a scenario model, which ciency factors for each configuration to choices — has not been encountered
uses the sol types to rack up the total calculate the “ops duration” correspon- until the most recent rover missions
number of “scenario sols” for that sce- ding to that scenario. Finally, a margin is (MSL and Mars 2018).
nario (in other words, the ideal number applied to determine the minimum sur- This work was done by Sharon L. Layback
of sols it would take to perform the sce- face lifetime required for that scenario. of Caltech for NASA’s Jet Propulsion Labora-
nario objectives). Then, the number of Typically, this level of analysis has not tory. Further information is contained in a
sols requiring ground in the loop is cal- been performed until much later in the TSP (see page 1).NPO-48262
GPU Lossless Hyperspectral Data Compression System
NASA’s Jet Propulsion Laboratory, Pasadena, California
Hyperspectral imaging systems on- of Multispectral-Image Data” (NPO- bility of GPUs to achieve a throughput
board aircraft or spacecraft can acquire 42517), NASA Tech Briefs, Vol. 30, No. 8 at least six times higher than that of a
large amounts of data, putting a strain (August 2006), page 26, which operates software implementation running on a
on limited downlink and storage re- on hyperspectral data and achieves ex- single-core CPU. This implementation
sources. Onboard data compression can cellent compression performance while provides a practical real-time solution
mitigate this problem but may require a having low complexity. The FL compres- for compression of data from airborne
system capable of a high throughput. In sor uses an adaptive filtering method hyperspectral instruments.
order to achieve a high throughput with and achieves state-of-the-art perform- This work was done by Nazeeh I. Aranki,
a software compressor, a graphics pro- ance in both compression effectiveness Didier Keymeulen, Aaron B. Kiely, and
cessing unit (GPU) implementation of a and low complexity. The new Consulta- Matthew A. Klimesh of Caltech for NASA’s Jet
compressor was developed targeting the tive Com mittee for Space Data Systems Propulsion Laboratory. For more information,
current state-of-the-art GPUs from (CCSDS) Standard for Lossless Multi- contact [email protected].
NVIDIA®. spectral & Hyperspectral image com- The software used in this innovation is avail-
The implementation is based on the pression (CCSDS 123) is based on the able for commercial licensing. Please contact Dan
fast lossless (FL) compression algorithm FL compressor. The software makes use Broderick at [email protected].
reported in “Fast Lossless Compression of the highly-parallel processing capa- Refer to NPO-48571.
Robust, Optimal Subsonic Airfoil Shapes
Ames Research Center, Moffett Field, California
A method has been developed to cre- selected perimeter locations for the ini- ding strength from the trailing edge of
ate an airfoil robust enough to operate tial airfoil shape; using CFD to deter- the airfoil is no greater than a selected
satisfactorily in different environments. mine the pressure distribution for the threshold value; a difference between
This method determines a robust, opti- airfoil shapes that are small perturba- any resonant frequency of the airfoil
mal, subsonic airfoil shape, beginning tions to the initial airfoil shape; and and the vortex shedding frequency is at
with an arbitrary initial airfoil shape, using an estimation method, such as a least equal to a threshold frequency dif-
and imposes the necessary constraints neural network, a support vector ma- ference; mass of the airfoil is no larger
on the design. Also, this method is flex- chine, or a combination thereof, to con- than a threshold mass value; and pres-
ible and extendible to a larger class of struct a response surface that models the sure value at each of a sequence of se-
requirements and changes in con- pressure distribution as a function of the lected locations along the surface of the
straints imposed. airfoil shape using the CFD data. Other airfoil differs from a corresponding ref-
In one embodiment, process steps in- process steps include using an optimiza- erence pressure value by no more than a
clude providing a specification of a de- tion algorithm to search the response threshold pressure difference value.
sired pressure value at each of a se- surface for the airfoil shape having the This work was done by Man Mohan Rai of
quence of selected locations on the required pressure distribution, and pro- Ames Research Center. Further information is
surface of a turbine airfoil; providing an viding at least one of an alphanumeric contained in a TSP (see page 1).
initial airfoil shape; providing a state- description and a graphical description Inquiries concerning rights for the commer-
ment of at least one constraint to which a of the modified airfoil shape. cial use of this invention should be addressed
final airfoil shape must conform; using Constraints may be drawn from the to the Ames Technology Partnerships Division
computational fluid dynamics (CFD) to following group, or may be one or more at 1-855-NASA-BIZ (1-855-6272-249). Refer
estimate a pressure value at each of the other suitable constraints: vortex shed- to ARC-14586-2
22 NASA Tech Briefs, January 2014