Inlet Dynamics and Compressor Surge

A numerical solution of the one-dimensional, unsteady, inviscid flow equations in a variable area duct, based on Lax's artificial viscosity technique, was developed to examine large amplitude transients, such as compressor surge, and their effect on mixed-compression inlet flow. The advantages and characteristics of the numerical method are briefly outlined. How to properly define surge, the appropriate numerical boundary conditions, and the sensitivity of inlet flow history to the surge-initiating mechanism are discussed. Representative experimental data are evaluated and compared with numerical results. Nomenclature A = flow area a = sound speed k = dissipative coefficient M = Mach number P = pressure T = temperature t = time u — velocity x — spatial coordinate 7 = specific heat ratio p — density \j/ = bleed flow Super scrip ts n = temporal index 0 = initial condition