A low-noise open rotor system is being tested in collaboration with General Electric and CFM International, a 50/50 joint company between Snecma and GE. Candidate technologies for lower noise will be investigated as well as installation effects such as pylon integration. The research program in both the low and high-speed wind tunnels is reviewed. Some detailed flowfield and acoustics measurements acquired for an internal NASA program are highlighted. The publically available research data is presented also

VanZante, Dale E.

NASA Technical Reports Server

20 
Open Rotor Research at NASA Glenn 
A low-noise open rotor system is being tested in collaboration with General 
Electric and CFM International, a 50/50 joint company between Snecma 
and GE. Candidate technologies for lower noise will be investigated as well 
as installation effects such as pylon integration. The research program in 
both the low and high-speed wind tunnels is reviewed. Some detailed 
flowfield and acoustics measurements acquired for an internal NASA 
program are highlighted. The publically available research data is 
presented also. 
https://ntrs.nasa.gov/search.jsp?R=20110011377 2019-08-30T15:39:03+00:00Z
National Aeronautics and Space Administration 
www.nasa.gov 
Open Rotor Research at NASA Glenn 
ERA Advanced Vehicle Concepts NRA discussion 
February 1, 2011 
Dale Van Zante 
Propulsion Sub-Project Engineer 
Environmentally Responsible Aviation 
Integrated Systems Research Program 
Outline!
2 
•  The Open Rotor test program 
•  Rig and facility details 
•  Low speed isolated/installed data 
•  Status 
Testing is supported by the Environmentally Responsible Aviation Project 
Data analysis efforts are supported by the Subsonic Fixed Wing Project 
Facility support is from the Aeronautics Test Program 
The NASA/GE Collaboration on Open Rotor Testing!
•  Objective: Explore the design space for lower noise while 
maintaining the high propulsive efficiency from a counter-rotating 
open rotor system.!
•  Approach: A low-noise open rotor system is being tested in 
collaboration with General Electric and CFM International, a 50/50 
joint company between Snecma and GE. Candidate technologies for 
lower noise will be investigated as well as installation effects such as 
pylon integration. 
Historical Baseline Blade Set 
12 x 10 blade count 
Non-proprietary geometry/data 
Export controlled 
Test Program Overview!
NASA/GE"
9x15 Low Speed Wind Tunnel"
NASA/GE"
8x6 High Speed 
Wind Tunnel"
NASA/GE/FAA
(CLEEN)"
8x6/9x15"
GE Gen-1 Blade Designs! GE Gen-2 Blade Designs!
Takeoff and 
Approach 
Conditions!
ERA 
Diagnostics! Cruise Conditions!
TO/Approach and 
Cruise Conditions!
• Aerodynamic 
performance!
• Acoustics"
• Hot Film 
flowfield 
measurements!
• Acoustic phased 
array!
• Farfield 
Acoustics with 
Pylon!
• Pressure 
Sensitive Paint!
• Stereo Particle 
Image 
Velocimetry!
• Acoustic 
Shielding!
• Aerodynamic 
performance"
• Near field 
unsteady 
pressure!
•  Aero and 
acoustic 
performance of 
optimized blade 
designs at low 
and high speed.!

The Open Rotor Propulsion Rig (ORPR)"
6 
750 SHP per rotor 
Rotating force balance: 
  430 Lbf thrust per rotor 
  550 ft-lb torque per rotor 
1/5 to 1/7 of Full Scale 
Independently controlled rotor 
speeds 
Digital telemetry units for and aft 
12 strain gage channels per rotor 
Adjustable rotor spacing 
Tare corrections to force balance data"
7 
Kulite, inter-rotor 
cavity, outer 
Kulite, inter-rotor 
cavity, inner 
Avg. rotor cavity pressure, 
outer 
Avg. rotor cavity 
pressure, inner 
Upstream 
face of 
Forward 
rotor 
Downstream 
face of 
Forward rotor 
The downstream rotor force, frdf, is calculated by multiplying the 
delta pressure term (delta from the freestream static pressure, pso) 
by the particular inter-rotor cavity pressure. 
Downstream 
rotor force 
Forward Rotor Downstream Force 
Acoustic Configuration"
8 
60” 
sideline 
18° forward to 
140° aft angles 
NASA/GE Collaboration  
9x15 Low Speed Wind Tunnel test!
9 
Test Matrix"
Freestream Mach number variation!
Blade pitch angle setting variation!
Series of RPMs at a set pitch!
Model angle of attack!
A detailed aerodynamic performance 
data set was acquired for all blade 
sets as well as acoustic 
measurements at 18 axial locations. 
Primary NASA researcher: John Gazzaniga 
ERA Diagnostics:  
Historical Baseline Installation effects (2)!
The presence of the CFMI pylon 
induces distortions into blade rows 
causing noticeable increase in the 
levels of the individual rotor 
harmonics. 
NASA Researcher: David Elliott 
1BPFa 
1BPFf 
2BPFf 
2BPFa 
1BPFf +1BPFa 
1BPFf +2BPFa 
5 dB 
Data Summary for Historical Baseline"
11 
!"#$%&'"( )* +"+ ,-.&/"0"1&2&3#% +4&/"0"1&2&3#% 5673890&:1;30<;#0 :;90&=30;&
>?+ @(? @ AB AB(C '"#; ?DE*F0E@G
>?H (>DI(?I(?? EBI@IBID A@(> A@(D '"#; ?DE*F0E@G
>?! @(? @ A@(> A@(D =8F0 GE)31E>@
>B+ @(? @ BB(C BC(J =8F0 GE)31E>@
>?= @(? @ AB AB(C =8F0 >@E)31E>@
,,&KLM @(?I&@(?? @IBID A@(> A@(D )8N;1 ?E+8%E>@
,,&KLM @(?I&@(?? @IBID BB(C BC(J )8N;1 BE+8%E>@
,,&OP* @(?I&@(?? @IBID BB(C BC(J )8N;1 BE+8%E>@
,,&OP* @(?I&@(?? @IBID A@(> A@(D )8N;1 AE+8%E>@
,,&OP*&Q+MM&,Q= @(? @ A@(> A@(D )8N;1 CE+8%E>@
,,&OP*&Q+MM&+,: @(? @ A@(> A@(D )8N;1 CE+8%E>@
,,&OP*&Q+MM&,Q= @(? @ A@(> A@(D )8N;1 JEP;RE>@
,,&OP*&Q+MM&+,: @(? @ A@(> A@(D )8N;1 JEP;RE>@
!"#$%&'
(
)
*+
*,-
*.
/01
/0(
/0)
/0*
/0+
/0,
/12
/10
3 blade pitches: TO Nom, Scaled TO, Approach 
Work is going on now to apply the tare corrections to this data. 
ERA Diagnostics:  
Historical Baseline Acoustic Shielding!
Finite acoustic barrier wall. Semi-infinite acoustic barrier wall. 
~34° 
~67° 
Short barrier, Forward position 
Test Matrix"
2 Barrier wall lengths!
2 Barrier wall positions!
Forward and Aft!
2 Rotor speeds!
2 Freestream Mach numbers!
NASA/GE Collaboration  
8x6 High Speed Wind Tunnel test!
13 
NASA C85-6031 NASA NAS3-24080, Task V Final Report 
Objectives: Aerodynamic 
performance and near field 
unsteady pressure measurements 
at cruise Mach number. 
Installation of ORPR into the 8x6 
began in December. 
Status!
14 
•  Isolated and pylon installed aero and acoustic data 
exist for the Historical Baseline Blade Set (F31/A31). 
•  Tare corrections are being applied to the data now. 
•  This constitutes that data set needed for system 
analysis. 
Federal Aviation Administration: CLEEN program 
Publications!
16 
Elliott, David M., “Initial Investigation of the Acoustics of a Counter Rotating Open Rotor Model With 
Historical Baseline Blades in a Low Speed Wind Tunnel,” to be presented at AIAA Aeroacoustics 
Conference, Portland, Oregon, June 2011. 
Stephens, David and Envia, Edmane, “Acoustic Shielding for a Model Scale Counter-rotation Open 
Rotor,” to be presented at AIAA Aeroacoustics Conference, Portland, Oregon, June 2011. 
Berton, Jeffery J., “Empennage Noise Shielding Benefits for an Open Rotor Transport,” to be 
presented at AIAA Aeroacoustics Conference, Portland, Oregon, June 2011. 
Hendricks, Eric, “DEVELOPMENT OF AN OPEN ROTOR CYCLE MODEL IN NPSS USING A MULTI-
DESIGN POINT APPROACH,” GT2011-46694, to be presented at Turbo Expo 2011, Vancouver, BC, 
June 2011. 
Van Zante, Dale, Gazzaniga, John, Eliott, David, and Woodward, Richard, “An Open Rotor Test Case: 
F31/A31 Historical Baseline Blade Set,” to be presented at ISABE 2011, Gothenburg, Sweden. 
September 2011. 
The ERA Diagnostics Program!
Acoustic 
Phased 
Array"
Farfield 
acoustics 
with Pylon"
Pressure 
Sensitive 
Paint"
Stereo 
Particle 
Image 
Velocimetry"
Acoustic 
Shielding"
The goal is a comprehensive data set that will identify noise sources and 
enable improved performance and acoustic modeling of open rotor 
systems. 
ERA Diagnostics:  
Detailed Historical Baseline flowfield measurements!
Low 
High 
Oil damage  
to PSP coating 
The 3D PIV measurements 
provide a wealth of 
information about the blade 
wakes and vortex track. 
NASA Researcher: Mark Wernet 
Leading edge 
vortex track 
Fwd Rotor 
Suction 
surface 
The Pressure Sensitive 
Paint measurements show 
phase locked static 
pressure on the surface of 
the rotating blade. 
NASA Researcher: Tim Bencic 
Tip vortex track 
Blade wake 
ERA Diagnostics:  
Historical Baseline Installation effects (1)!
19 
CMFI Pylon 
Array 
Peak Level 
No Pylon 
Array 
Peak Level 
The location of peak noise level in the 
phased array map changes in the 
presence of the CFMI pylon indicating 
a change in the relative strength of 
sources. 
NASA Researcher: Gary Podboy 
Flush Kevlar Acoustic 
Cover 


Open Rotor Research at NASA Glenn

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