methods to measure the high angle and mach number of a probe

摘要

A method for obtaining angle of attack from measured pressure values with a probe (10) having angle measuring ports and a pitot port. A table (36) of known values of angle of attack relative to the pressure ratio of measured Mach numbers determined by P 1 /P m is stored in memory and used when P 1 is greater than the pressure sensed at the pitot port (P t'm ). P 1 is the pressure measured at the one of the angle measuring ports (18) that is higher than the pressure measured at the other angle measuring port (20), and P m is an average of the pressures at the angle measuring ports (18, 20). The correlation of the ratio of measured pressures on the probe (10) relative to angle of attack is determined using the known values P 1 /P m at different angles of attack either in wind tunnel tests or by computer simulation. The values that have been stored then can be retrieved to solve for the correct angle of attack.