Executive Summary : | Impinging jets are widely used in many industrial applications such as annealing of metal sheets, de-icing of aircraft wings, cooling of turbine blades, gas turbine combustor liner and electronic cooling. The application of interest for the present work is cooling of the gas turbine combustor liner. The cross flow is a crucial impingement cooling phenomenon, and it has a complex impact on heat transfer. In the present proposal efforts are made to augment impingement heat transfer by improving coolant efficiency, temperature uniformity and reducing crossflow. This is done by two means: firstly, by modifying jet nozzle system with inclusion of turbulators; and secondly, by incorporating vortex generators over the target plate. The investigation will be carried for different arrangement and shapes of jets. The number of nozzles, its shape and configuration affect both heat transfer and flow structure. Multiple jets present extra complexity and fluid structure instability. Understanding the complex flow field generated by interaction on various configurations of neighboring jets in crossflow is the objective of the present work. Further the effect of size and shape of vortex generators on the impingement heat transfer and its corresponding flow physics will be explored. This work is presumed to provide insights on heat transfer enhancement of multi-jet impingement with upstream turbulators on nozzle plate along with vortex generators in the downstream. This configuration is expected to lower requirements of coolant flow rate by 10% due to reduced effect of crossflow. An overall increase in Nusselt number by 20% is also expected. |