FILM-COOLING EFFECTIVENESS IN A PARTICLE-LADEN FLOW

A computational method is developed to evaluate the cooling effectiven ess of a tangential slot in a particle-laden flow. The physical proble m analyzed involves the tangential injection of a coolant at a wall su bjected to convective heating from a turbulent boundary layer and radi ative heating from hot particles. Previous published analyses did not include radiative or particle effects. The boundary-layer equations, i ncluding energy and species conservation, are solved using a finite di fference scheme. The particle transport equation is also solved by a f inite difference technique. A two-dimensional formulation for the solu tion of the radiative equation of transfer is developed using the sphe rical harmonics method. This formulation is different from those previ ously published in that it solves for an azimuthally integrated form o f the intensity. This approach reduces the number of unknowns in the s olution and is therefore more computationally efficient. Particle opti cal properties are obtained using the Mie scattering theory. A paramet ric study is performed to determine the effects of wall emissivity and other parameters on cooling effectiveness and particle deposition on the wall.