TOTAL TEMPERATURE RECOVERY CHARACTERISTICS TEST TECHNIQUE BASED ON TOTAL PRESSURE CALIBRATION WIND TUNNEL

摘要

It is difficult to obtain the recoverycharacteristics of a total temperature probe dueto limited number of dedicated wind tunnel forrecovery characteristics calibration, complextest procedure, long test period and high cost.Feasibility study of calibrating recoverycharacteristics using ordinary total pressurecalibration wind tunnel was conducted,including the test principle and procedure, theanalysis of the major influencing factors anduncertainty estimation of the measurement, etc.The major influencing factors include thevariation of air temperature surrounding theprobe under test, the characteristics of the flowfields of the wind tunnel low speed section, heatloss of the wind tunnel flow nozzle, heatexchange between the nozzle free jet and theprobe and the heat conduction along thesupport of the probe. On the basis of thefeasibility study, a simple total temperaturerecovery test system was established based onthe ordinary total pressure calibration windtunnel. Several types of probes were testedusing the system. Uncertainty analysis ofrecovery factor was carried out taking intoaccount static calibrations curve of probe withdata-acquisition channels fitted by least squares.The test results and analysis proved the commonsubsonic wind tunnel can be used to quantify therecovery characteristics of total temperatureprobe, which can be used in design verificationto distinguish different probes design in terms oftheir recovery factors. The study explored a lowcost technique to acquire recovery factors usingambient air total pressure calibration windtunnel. Experience was gained in boththeoretical investigation and application of thetest. Valuable test data accumulated can also beused for comparison with the results from hotwind tunnel in the future to verify the accuracyof the method.