Analysis of Lumped Deterministic Source Terms and Their Sub-Components in a Stage 1 High Pressure Turbine Rotor
A GE proprietary code has been used to extract the Lumped Deterministic Source Terms (LDSTs) for the five governing equations: continuity, r, θ, z-momentum, and energy; as well as the two turbulence equations, from a converged unsteady time-averaged flow field. LDSTs are the opposite of the fluxes contained in the solution residuals for a time averaged flow field. They describe the cumulative effects of unsteadiness contained in the time-averaged solution. It has been shown that the addition of these terms to the steady residual operator in this code will drive the solution to the time averaged unsteady solution. The contributions of the LDST components, i.e. the residuals from the Euler, viscous and numerical dissipation, were studied to assess how they build the total LDST. Another approach to computing the inviscid source terms directly from time series data was also compared to the respective total and shows that the LDSTs are composed primarily of the inviscid component terms. In addition, attaining a time-averaged solution with a steady solver has been found to be sensitive to the boundary conditions. Results from one boundary condition set are presented in an error form to gauge the impact on the solution.