Calibration of a Flow Angularity Probe with a Real-time Pressure Sensor PDF Download

Author: Brock Joseph Anthony Pleiman
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Languages : en
Pages : 150

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Book Description
In airframe propulsion integration, the pressure recovered at the beginning of the inlet in comparison to the end of the inlet is a critical design point. Studies conducted by the Air Force Research Lab show that a loss in recovery pressure directly and adversely relates to the change in range of the aircraft. For that reason, accuracy of pressure instrumentation at the aerodynamic interface plane, or the interface between the end of the inlet and the beginning of the engine, is critical. Historically, data from experimental tests at the aerodynamic interface plane have mostly been reduced into time-averaged and time-independent pressures; however, current engine manufacturers are increasing focus on the angularity of the flow entering the engine. Currently airframe propulsion integration test programs require multiple runs to test each configuration with different sensor types to measure the time-dependent and time-independent pressure values, as well as, the angularity of the flow. Testing the same configuration multiple times can quickly become expensive in larger, production tunnels so a new probe design capable of capturing the time-independent and time-dependent pressures, in conjunction with the angularity of the flow has been designed.In order to determine whether the design of the probe is adequate for capturing all three variables similar to historical results shown by Paul[1], Kulite[2] and Arrend[3], a calibration must first be completed followed by the collection of additional data points which provide calibration validation. In order to calibrate the new probe, previously calibrated instrumentation will be used as a 0́−truth0́+ model. To ensure that the measurement uncertainty due to test set-up is comparable, the technique and test approach will be modeled after the calibration of a series of 5-hole probes calibrated at Wright Patterson Air Force Base.This thesis will document the experimental set-up, test approach, data acquired, data reduction and measurement uncertainty for a series of Mach numbers to determine if a 5-hole probe with a time-dependent pressure sensor in the center port is capable of accurately measuring steady state total and static pressure, Mach number, angle of attack and yaw, and dynamic content simultaneously.After running the calibration, it was found that the steady-state total and static pressure, angle of attack and yaw uncertainty are similar to the results previously published by Gallington[4], Paul[1] and Semmelmayer[5] if the Mach number is greater than Mach 0.2. The amplitude of nearly all of the frequencies detected in the experiment increased with angle of attack, angle of yaw and Mach number therefore leading to an increased RMS about the average reading of the sensor; however, a relationship between the RMS and angle of attack, angle of yaw and Mach number was found. This relationship showed that calibrating the RMS of the probe at an angle of attack to what the RMS of the flow would have been if the probe were axially aligned may be possible. Although the initial results of the RMS relationship are promising, the final results lack closure and require additional testing. In conclusion the probe is capable of accurately measuring total and static pressure, Mach, angle of attack and yaw while the axially aligned fluctuations require more research to validate the proposed equation.