| The dynamic engine simulation code, GETRAN, was modified and improved by the addition of two component subroutine modules. The first module included was a one-dimensional wave rotor simulation code, WR1D. The wave rotor is a gasdynamic rotary device that functions as series of shock tubes designed to function in a flow loop with the engine's combustor. The device provides an increase in the total pressure to the turbine component and thereby increases total power production of the overall engine. After equilibrium conditions were achieved for a helicopter turboshaft engine, two transient simulations were conducted to test the interaction of the wave rotor with surrounding turbomachinery. The simulations conducted were a deceleration and acceleration of the combustor to test surge performance, and a simulated pressure disruption due to high angle of attack maneuvers. The wave rotor resisted the tendency to surge in acceleration and was quick to respond to inlet pressure fluctuations. The second module was an original row-by-row solution method for the turbine flow conditions that included, as a user option, the ability to cool turbine blades. The heat transfer and blade cooling methodology was tested by simulations of the above helicopter engine without the wave rotor, and for a GT-9 power generation gas turbine. Calculated results from the two simulations for a variety of blade cooling and non-cooled blade options conformed to expected results. No experimental data was available for either code modifications validation. |
