AIAA Paper 2006-1093. Presented at the 44th AIAA Aerospace Sciences Meeting and Exhibit, January 9, 2006, pages 1-11. This article is in the public domain. Published by American Institute of Aeronautics and Astronautics.
NOTE: At the time of publication, the author Russell M. Cummings was on sabbatical leave from Cal Poly.
Determining the local stream thrust (a vector quantity) from a measured pitot pressure (a scalar quantity) requires either knowledge of the flow direction, or a probe shape that compensates for flow direction. This compensation would ideally make the measured pressure directly proportional to the component of momentum along the probe axis. The flow angle sensitivity required to resolve this component of momentum was determined theoretically previously. A proposed probe nose shape was analyzed using CFD and found to produce flow angle sensitivity close to the required sensitivity. The proposed nose shape was also tested in a wind tunnel at Mach 1.67, 2.45, and 3.48 at angles of attack from 0 to 15 degrees. The test results indicate that the flow angle sensitivity of the proposed nose shape agrees with the required sensitivity to within 1% up to a flow angle of 15°. The current work extends the original theoretical development for the optimum nose shape to include viscous affects and surface curvature. The new second-order theory agrees well with experimental results for both the stream thrust probe as well as other, independent data. Further work can be done to refine the theory.