OPTIMAL CONTROL OF A HIGH PERFORMANCE WIND TUNNEL

Stringent accuracy and safety tolerances together with the demand to save operational costs require the optimal control of high performance wind tunnels. Based on the thermo-fluidmechanical balance principles a mathematical model of a cryogenic wind tunnel with lumped parameters is developed which is bilinear with time-delay in the mass flows and quadratic in the fan speed. Time optimal controls are discussed for this multivariable model depending on the variation of the state and control constraints and on the location of the control inputs. The computational procedure used is a direct shooting method with optimal discretization.