Numerical analysis of the convective heat transfer in a combustor cooling jacket

Abstract: In any combustors and chemical reactors, to achieve high efficiency it is very important to maintain the high gas temperature inside the combustion chamber without significant deterioration of the materials of the walls. Thus, a critical aspect of the design of a combustor or reactor is the development of a method to cool the inner walls of a combustor such that the temperatures on the inner wall are well below the temperature a material can sustain. A typical method to cool a combustor chamber is to use a cooling jacket adjacent to the inner wall of the combustor. In general, the efficiency of this cooling jacket depends on the heat removal capability of the cooling water and the flow channel geometry. It is critically important to control these parameters to enhance the performance of the combustion chamber by decreasing the inner wall temperature below its material limit Sφ : source term in the generic property φ Vr ,Vθ , Vz : reduced velocities in the r, θ , and z direction respectively [m/s] T : temperature [ºC] Tinn : inner temperature [ºC] T∞ : ambient temperature [ºC] U0 : inlet velocity [m/s] Greek ρ : density [kg/m3] φ : generic property μ : dynamic viscosity [kg/m-s] Γ : diffusivity for the generic property φ Ω : angular velocity [rad/s] This study considers a cylindrical combustor, rotating around its axis. A detailed investigation of the fluid flow and heat transfer processes throughout the cooling jacket is performed. A two-dimensional axial symmetric Navier-Stokes equations and energy equation as a conjugate problem are solved. The flow patterns and temperature distributions of the cooling jacket under the effect of rotation are presented. Also, local friction factor and Nusselt number are calculated along the axial direction