Effect of Correlation Strength Uncertainty on Bayesian Calibration of Gas Turbine Simulator

Effect of uncertainty in the correlation strength of Gaussian process on Bayesian calibration of the gas turbine engine simulator is demon-strated. The framework is investigated for the Gamma and uniform prior on the correlation strength. Inference of correlation strength us-ing full Bayesian analysis and the maximum-a-posteriory estimation is compared. The methodology is demonstrated for a simulation of single spool turbofan engine using hypothetical test bed engine data. Nomenclature A = area, m2 CN = corrected speed f = probability density function F = thrust, N H = altitude, m I = polar moment of inertia, kg.m2 M = flight Mach number N = spool speed, rev/s P = pressure, Pa PR = pressure ratio Pr = probability R = gas constant, J/kg.K T = simulator TR = temperature ratio V = lumped volume, m3 W = mass flow rate, kg/s x = vector of control input Y = system response α, λ = hyperparameters of the Gaussian process γ = isentropic index ǫ = measurement uncertaint