Computation of Discrete Slanted Hole Film Cooling Flow Using the Navier-Stokes Equations.

摘要

An Analysis and computational procedure have been developed for predicting the flow and heat transfer which results from coolant injection through a single row of round holes oriented at an angle to a flat surface with the injection and freestream velocity vectors coplanar. This method solves the compressible Navier-Stokes equations and utilizes 'zone embedding', surface-oriented coordinates, interactive boundary conditions, and an efficient, split LBI scheme. The approach treats the near-hole flow region where the complex film cooling flow is initially established. The initial studies considered only laminar flow in order to develop the computational procedure without the added complications of turbulence modeling. Calculations were performed on a coarse mesh at a blowing rate of 0.1 for both normal injection and injection at 45 degrees through a circular hole with the computational domain extending into the coolant hole. The results obtained were qualitatively reasonable and demonstrated the capability of the procedure for treating film cooling injection flows without simplifying assumptions in the near-hole flow region. The procedure was extended to turbulent flows and a calculation was performed for an injection angle of 35 degrees with a lateral hole spacing of three diameters. The results for this case display the expected large secondary flow development as a result of the interaction between the main stream flow and the injected fluid. Also, the temperature distribution predictions exhibit good qualitative agreement with experimental data with the quantitative discrepancies apparently due to either the turbulence model or inadequate grid resolution.