Effect of Flow-Acoustic Resonant Interactions on Aerodynamic Response of Transitional Airfoils

65 Pages·2017·4.86 MB·English

by  Joseph Hayden

Dissertations and Theses
12-2016
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Joseph Hayden
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i

EFFECT OF FLOW-ACOUSTIC RESONANT INTERACTIONS ON
AERODYNAMIC RESPONSE OF TRANSITIONAL AIRFOILS

A Thesis
Submitted to the Faculty
of
Embry-Riddle Aeronautical University
by
Joseph Hayden

In Partial Fulfillment of the
Requirements for the Degree
of
Master of Science in Aerospace Engineering

December 2016
Embry-Riddle Aeronautical University
Daytona Beach, Florida

iii

TABLE OF CONTENTS
LIST OF TABLES ............................................................................................................. iv
LIST OF FIGURES ........................................................................................................... v
SYMBOLS ........................................................................................................................ vii
ABBREVIATIONS ......................................................................................................... viii
ABSTRACT ....................................................................................................................... ix
1. Introduction .......................................................................................................... 1
1.1. Motivation ................................................................................................................... 1
1.2. Airfoil Noise ............................................................................................................... 2
1.3. Ikeda Results ............................................................................................................... 2
1.4. Objective of Current Work ........................................................................................ 4
2. Numerical Models ................................................................................................ 5
2.1. The ILES Code ........................................................................................................... 5
2.2. The Turbulence Model ............................................................................................... 8
3. Results .............................................................................................................. 12
3.1. NACA-0012: Mach 0.0465 Re 140,000 ................................................................. 13
3.1.1. Pressure Spectra and Lift History ........................................................................ 13
3.1.2. Boundary Layer Statistics .................................................................................... 17
3.2. SD7003: Mach 0.0465 Re 140,000 ......................................................................... 23
3.2.1. Pressure Spectra and Lift History ........................................................................ 23
3.2.2. Boundary Layer Statistics .................................................................................... 27
3.3. NACA-0012: Mach 0.2 Re 10,000 ......................................................................... 32
3.3.1. Pressure Spectra and Lift History ........................................................................ 33
3.3.3. Boundary Layer Statistics .................................................................................... 37
3.4. SD7003: Mach 0.2 Re 10,000 ................................................................................. 41
3.4.1. Pressure Spectra and Lift History ........................................................................ 42
3.4.3. Boundary Layer Statistics .................................................................................... 45
4. Conclusion .......................................................................................................... 49
REFERENCES ................................................................................................................. 53
iv

LIST OF TABLES

Table 3.1 Geometric angle of attack investigated for NACA-0012 Re=140,000 ............. 13
Table 3.2 Geometric angle of attack investigated for SD7003 Re=140,000 .................... 23
Table 3.3 Geometric angle of attack investigated for NACA-0012 Re=10,000 ............... 33
Table 3.4 Geometric angle of attack investigated for SD7003 Re=10,000 ...................... 41
v

LIST OF FIGURES

Figure 1.1 Time-averaged lift curves of 2-D simulation results for NACA-4x06 airfoils
(Ikeda et al., 2014) .............................................................................................................. 3
Figure 3.1 Surface Pressure Spectra Comparison of NACA-0012 ................................... 14
Figure 3.2 Coefficient of Lift vs. Non-Dimensional Time Comparison for NACA-0012 15
Figure 3.3 Comparison of Fast Fourier Transform of Lift for NACA-0012 .................... 15
Figure 3.4 Time-averaged CL vs. Angle of Attack Comparison for NACA-0012 ........... 16
Figure 3.5 Time-averaged CD vs. Angle of Attack Comparison for NACA-0012 ........... 17
Figure 3.6 Instantaneous Z-Vorticity Contours for NACA-0012 ..................................... 18
Figure 3.7 Time-averaged U-Velocity Contours NACA-0012 ......................................... 19
Figure 3.8 Mean Pressure Coefficient Comparison for NACA-0012 ............................... 19
Figure 3.9 RMS Pressure Coefficient Comparison for NACA-0012 ............................... 20
Figure 3.10 Skin Friction Coefficient Comparison for NACA-0012 ............................... 21
Figure 3.11 U-Velocity Profile Comparison for NACA-0012 ......................................... 21
Figure 3.12 RMS of U-Velocity Profile Comparison for NACA-0012 ............................ 22
Figure 3.13 Surface Pressure Spectra Comparison of SD7003 ........................................ 24
Figure 3.14 Coefficient of Lift vs. Non-Dimensional Time Comparison for SD7003 ..... 24
Figure 3.15 Comparison of Fast Fourier Transforms of Lift for SD7003 ........................ 25
Figure 3.16 Time-averaged CL vs. Angle of Attack for SD7003 ..................................... 26
Figure 3.17 Time-averaged CD vs. Angle of Attack for SD7003 ..................................... 26
Figure 3.18 Instantaneous Z-Vorticity Contours for SD7003 .......................................... 27
Figure 3.19 Time-averaged U-Velocity Contours SD7003 .............................................. 28
Figure 3.20 Mean Pressure Coefficient Comparison for SD7003 .................................... 29
Figure 3.21 RMS Pressure Coefficient Comparison for SD7003 ..................................... 29
Figure 3.22 Skin Friction Coefficient Comparison for SD7003 ....................................... 30
Figure 3.23 U-Velocity Profile Comparison for SD7003 ................................................. 31
Figure 3.24 U-rms Velocity Profile Comparison for SD7003 .......................................... 32
Figure 3.25 Acoustic Spectra Comparison of NACA-0012 ............................................. 34
Figure 3.26 Coefficient of Lift vs. Non-Dimensional Time Comparison for NACA-0012
........................................................................................................................................... 35
Figure 3.27 Comparison of Fast Fourier Transforms of Lift for NACA-0012 ................. 35
Figure 3.28 Time-averaged CL vs. Angle of Attack for NACA-0012 .............................. 36
vi

Figure 3.29 Time-averaged CD vs. Angle of Attack for NACA-0012 .............................. 37
Figure 3.30 Instantaneous Z-Vorticity Contours for NACA-0012 ................................... 38
Figure 3.31 Time-averaged U-Velocity Contours NACA-0012....................................... 39
Figure 3.32 Mean Pressure Coefficient Comparison for NACA-0012 ............................. 40
Figure 3.33 RMS Pressure Coefficient Comparison for NACA-0012. ............................ 40
Figure 3.34 Skin Friction Coefficient Comparison for NACA-0012 ............................... 41
Figure 3.35 Acoustic Spectra Comparison of SD7003 ..................................................... 42
Figure 3.36 Coefficient of Lift vs. Non-Dimensional Time Comparison for SD7003 ..... 43
Figure 3.37 Comparison of Fast Fourier Transform of Lift for SD7003 .......................... 43
Figure 3.38 Time-averaged CL vs. Angle of Attack Comparison for SD7003 ................. 44
Figure 3.39 Time-averaged CD vs. Angle of Attack Comparison for SD7003 ................. 45
Figure 3.40 Instantaneous Z-Vorticity Contours of SD7003 ............................................ 46
Figure 3.41 Time-averaged U-Velocity Contours for SD7003 ........................................ 47
Figure 3.42 Mean Pressure Coefficient Comparison for SD7003 .................................... 48
Figure 3.43 RMS Pressure Coefficient Comparison for SD7003 ..................................... 48
Figure 3.44 Skin Friction Coefficient Comparison for SD7003 ....................................... 48
Figure 4.1 Instantaneous contours of streamwise velocity (Kurelek and Yarusevych 2016)
........................................................................................................................................... 51
vii

SYMBOLS

ρ Density
p Pressure
T Temperature
u Tangential Velocity
v Normal Velocity
w Spanwise Velocity
φ Flux component
L Turbulent Length
τ Time Scale
k Wave Number
ω Frequency
I Turbulence Intensity
α Angle of Attack
c Chord Length
U Freestream Velocity
viii

ABBREVIATIONS

AFL Acoustic Feedback Loop
dB Decibel
L Lift
D Drag
Re Reynolds Number
M Mach Number
ILES Implicit Large Eddy Simulation
RFG Random Flow Generation
AoA Angle of Attack
Hz Hertz
RMS Root Mean Squared
C Lift Coefficient
L
C Drag Coefficient
D
FFT Fast Fourier Transform
T-S Tollmien-Schlichting
K-H Kelvin-Helmholtz
C Skin Friction Coefficient
f
C Pressure Coefficient
p
DNS Direct Numerical Simulation
ix

ABSTRACT

Hayden, Joseph MSAE, Embry-Riddle Aeronautical University, December 2016. Effect of
Flow-Acoustic Resonant Interactions on Aerodynamic Response of Transitional Airfoils.

A high-accuracy numerical study is conducted to examine the impact of flow-acoustic
resonant interactions on the aerodynamic response of symmetric and cambered airfoils in
the realistic transitional flow regimes with Re =140,000 and M=0.0465 as well as the low
c
Reynolds number flow regime with Re =10,000 and M=0.2. The symmetric NACA-0012
c
and the cambered SD7003 airfoils are investigated at various angles of attack that have
been found previously to include both the tone and no-tone producing regimes, with
specific focus on the aerodynamic lift response. Additional simulations are conducted
with a low-intensity synthetic turbulence introduced upstream of the airfoils in order to
trip the boundary layer on the airfoil surface and thus eliminate the acoustic feedback
loop as the tone-generating mechanism. The current work focuses on comparing the lift,
drag, and lift to drag ratio curves in the uniform vs. turbulent flow cases to determine the
impact of the acoustic feedback loop on the airfoil aerodynamic performance for both
realistic and low Reynolds number flow conditions.