Over the last three decades Bihrle has conducted static and dynamic wind tunnel tests on over 150 civil and military configurations – from trainers to powered military aircraft test – from general aviation to hypersonic research vehicles. The acquisition, reduction and
analysis of the test data for this broad range of vehicles has resulted in an unprecedented exposure to configuration aerodynamic behavior and test requirements.
As a result of this experience, Bihrle has received over 20 SBIR Phase I and Phase II awards for the development and application of advanced test techniques in the commercial marketplace. Using their own specialized test facility, as well as partner facilities, Bihrle is able to
offer a wide range of proven test capabilities for applications ranging from configuration development, diagnostic testing, to simulation database acquisition.
Using customer supplied models, or assisting the customer in the development of the most effective test article, Bihrle can integrate one or all of these test methods into a productive, cost effective test program:
Static Testing
From testing full scale aircraft to evaluating the effect of multiple vehicle interactions, Bihrle can accommodate a wide range of testing needs. Using specially designed tunnel interface hardware, Bihrle can give their customer the ability to acquire static test data through
±180° angle of attack, ±90° of sideslip. From low angle of attack through the extremes of a vehicle’s envelope, Bihrle can provide the data needed to characterize any aircraft’s behavior.
Success Stories:
Formation Flight Testing
Dynamic Testing
Since establishing a commercially viable dynamic test capability in the NASA 20 foot vertical tunnel in 1976, Bihrle has been the sole U.S. provider of rotary (wind axis) dynamic data. Now having conducted dynamic tests on over 100 configurations to assess and simulate their maneuver,
departure and spin characteristics, Bihrle has demonstrated the successful application of these data throughout the aviation industry. Bihrle has also developed the ability to acquire body axis (forced oscillation) test data, and recent research has revolutionized how the data is
acquired, reduced and applied in analysis and simulation. Bihrle has also developed the capability to examine the complex interaction of body axis damping characteristics in the presence of a wind axis motion (typical of departures, oscillatory spins, and other departed conditions). The
ability to use the same model and facility to collect a comprehensive static and dynamic database makes the acquisition of these data early in a development program a cost effective reality.
Success Stories:
T-45 Inverted Spin Mode and Hinge Moment Testing
General Aviation Configuration Development Support
Review of Dynamic Testing SBIR Results
F18E/F Rotary Testing, Spin Mode Pressure Testing Prediction and Database
Movies:
Rotary Testing *
Roll Oscillation *
Combined Motion
Powered Testing
The continuing application of efficient propeller driven power sources in civil aircraft and military Unmanned Air Vehicle (UAV) applications has required the evaluation of the propeller slip stream aerodynamic effects. Unfortunately, past attempts at collecting this data required the
development of complex, expensive test articles, as well as cumbersome test practices. Working with the latest in electric power technology, Bihrle has developed a new powered testing application that uses the same models as in their static and dynamic test applications, in an
arrangement that eliminates the mechanical interaction of the power section and the airframe. This approach allows the accurate decoupling of the aerodynamic interaction and the thrust and propeller inertia. The power effects can now be acquired in both static and dynamic conditions,
using the same low cost model. Bihrle has also developed a new, more physically appropriate test state representation; consequently, the direct evaluation of the thrust effects in analysis and simulation applications is now possible.
Success Stories:
Advanced Trainer Powered Testing
The Development of the Skytote UAV
Pressure Testing
The analysis and understanding of complex flowfield effects has frequently involved the use of complicated, expensive external flow visualization methods such as water tunnels, Particle Image Velocimetry (PIV), Laser Doppler Velocimetry (LDV), or other methods. Besides the difficulty
of acquiring these data, particularly in a global manner, the relationship of the results to any vehicle force and moment data can be difficult to establish. Bihrle has attempted to address these short comings by developing a global (or local) pressure testing application that allows
the customer to visualize the surface pressures on the components of the vehicle. Using the latest electronic pressure sensing technology, these data can be collected concurrently with force and moment data during both static and dynamic test conditions. The surface pressure data can be
time averaged or acquired as a function of time. These test methods have been used to evaluate specific component effects, as well as the effect of a configuration change’s local and global flowfield interaction. More detailed understanding of aircraft dynamic behavior can be
achieved by examining the pressure distribution as a function of the dynamic motion. Control surface hinge moments can also be integrated from the surface pressure data. The integration of the pressure taps into the basic static and dynamic model can be accomplished for a modest
additional cost.
Success Stories:
Full-scale F-15 Forebody Testing
Race Car Windshield Test
X-31 Dynamic Pressure Wind Tunnel Test
