Comparison of Pressure Fields Around a Five-Hole Probe and Kiel Probe

The kiel probe is essentially a pitot probe with a shroud around its measurement port and is typically considered the superior device for measuring total pressure in a flowfield, while the five-hole probe can provide total pressure as well as information on three-dimensional velocities. A recent experimental test program in a compressible wind tunnel allowed the comparison of total pressures obtained with a kiel probe and a five-hole probe, where the two were not always in agreement. This paper uses both experiment and computational fluid dynamics to explore the difference in behavior between the two probes at five Mach numbers between 0.19 and 0.42 over 30 degrees of incoming flow angle at increments of 6 degrees. Results show the kiel probe’s realized total pressure deviates no more than 0.8% over the range of angles and Mach numbers, while the five-hole probe deviates up to 13.6%. Simulations provide local flowfield properties around each probe and highlight why the kiel probe provides the more accurate measurement of total pressure over a greater range of flow angles and Mach numbers.