Numerical simulation on turbulent flow and heat transfer in cooling duct with discrete-cross ribs on the opposite walls

Numerical simulation was conducted to investigate the turbulent flow and heat transfer in a cooling duct with discrete-cross ribs on two opposite walls at Reynolds number of 1×10 ⁴~20×10 ⁴ Seven cases with different angles between ribs and flow direction were calculated:θ=15° to 45°. Results show that: (1) The averaged Nusselt number decreases as the cooling inlet Reynolds number increases. At the meantime, the friction factor increases significantly and the comprehensive heat transfer efficiency gets lower. (2) The characteristics of heat transfer and turbulent flow are evidently effected by angles between ribs and flow direction. At the same Reynolds number, the case of θ=45° has the maximum averaged Nusselt number ratio and friction factor ratio while the case of θ=15° has the minimum one. Take one to another, the case of θ=15° has the best comprehensive heat transfer efficiency.