Dynamic calibration and validation of an accelerometer force balance for hypersonic lifting models

Area of Science:

• Aerospace Engineering
• Hypersonic Aerodynamics
• Experimental Fluid Dynamics

Background:

• Accurate measurement of aerodynamic forces and moments is critical for vehicle design.
• Short-duration hypersonic shock tunnels present unique challenges for instrumentation.
• Existing force balance technologies may have limitations for complex geometries.

Purpose of the Study:

• To design and develop an accelerometer-based force balance for measuring drag, lift, and rolling moment.
• To calibrate and validate the force balance using dynamic techniques.
• To assess the balance's performance on a blunt-nosed, flapped delta wing in hypersonic flow.

Main Methods:

• Developed an accelerometer-based force balance system.
• Employed a convolution technique for calibration and validation.
• Utilized hammer pulse tests to obtain impulse response functions.
• Performed Fast Fourier Transform (FFT) analysis on balance output.
• Conducted surface pressure measurements using high-frequency transducers.
• Tested the delta wing at various angles of incidence (0-15 degrees).

Main Results:

• Successfully calibrated the force balance using dynamic methods.
• Obtained impulse response functions for axial, normal, and angular components.
• Measured time histories of aerodynamic forces and moments under hypersonic conditions.
• Demonstrated good agreement between force balance data and surface pressure measurements.
• Validated the balance's capability for complex aerodynamic geometries.

Conclusions:

• The developed accelerometer-based force balance is a reliable tool for hypersonic aerodynamic research.
• Dynamic calibration techniques provide accurate system response functions.
• The balance is suitable for complex lifting aerodynamic shapes in ground-based hypersonic facilities.
• This technology advances the measurement capabilities in hypersonic testing.