Research On Performance Correction For Turboshaft Engine With Small Deviation In Altitude Simulation

As a result of the deviation in the equipment and operators, small deviation in environmentalsimulation inevitably exists in the turboshaft engine altitude simulating test. Traditionalsimilarity-conversion formula is not applicable with the special structure of turboshaft engine, so itis necessary to do research on the performance correction method of the turboshaft engine in thealtitude simulating test.Firstly, method of varying specific heat capacity was used to build up the component-levelnonlinear model of the turboshaft. And then test data were used to increase the accuracy of themodel. It has been shown that the the accuracy of the corrected model was obviously improved.The deviation of the main performance parameters in the ground state was less than1%, whichverified the effectiveness of the model.Secondly, through the simulation of turboshaft model, the influences of small deviation types(including inlet total pressure, inlet total temperature, outlet back pressure) on the mainperformance parameters of the turboshaft were studied, including single parameter deviation,double parameters’ deviations and triple parameters’ deviations. On the condition of remaining thespeed of the gas turbine unchanged, it was found that the variations of the main engineperformance parameters and the small deviations had shown a good linear rule and the variationsof the performance parameters and deviations met the principle of linear superposition.In the end, according to the analysis of the environmental small deviation to the performanceparameters of the turboshaft engine, the linear matrix correcting method which treated theenvironmental deviation as the independent variable and the engine performance parametersdeviation as the dependent variable was put forward, using a set of correcting matrices based onthe different working conditions of turboshaft engine. Then the deviation of the performanceparameters could be estimated directly on the basis of actual environmental simulation deviations.Plenty of simulations and high altitude test results show that the method had higher performancecorrecting accuracy on turboshaft engine.The matrix correcting method of turboshaft engine which was put forward in this paper hasbeen applied successfully in the turboshaft engine altitude simulation test.