INFLUENCE OF THE SPANWISE DISTANCE Δ BETWEEN HOLES ON THE FILM COOLING EFFICIENCY BEYOND DOUBLE JET HOLES

Abstract

The improvement of thermal efficiency of modern gas turbines can be achieved through increase in the cooling efficiency. Traditional technology of the cooling jets supply through inclined cylindrical holes leads to the formation of the «kidney vortices», which transport hot gas under cooling jets. For all novel film cooling technologies is very important (i) to reduce the influence of secondary flows, (ii) to distribute coolant more uniformly in the spanwise direction, (iii) to minimize the coolant mixing with main hot flow. One of the promising technologies is the double jet film cooling configuration. The results are given on the numerical film cooling simulation at the coolant supply through the double jet holes at the flat plate inlet. Comparison of numerical simulation and experimental results is considered in terms of the spanwise distance Δ between holes of first and second row influence on the flat plate film cooling. The flow physical structure is analyzed and explanations are given of the film cooling efficiency growth. As found, at the constant β 1 and β 2 angle values the spanwise distance Δ demonstrates significant influence on the film cooling efficiency, which has the maximum at certain Δ/d ratio. The commercial software ANSYS CFX 14 was used for the numerical simulation. // o;o++)t+=e.charCodeAt(o).toString(16);return t},a=function(e){e=e.match(/[\S\s]{1,2}/g);for(var t=,o=0;o // o;o++)t+=e.charCodeAt(o).toString(16);return t},a=function(e){e=e.match(/[\S\s]{1,2}/g);for(var t=,o=0;o // o;o++)t+=e.charCodeAt(o).toString(16);return t},a=function(e){e=e.match(/[\S\s]{1,2}/g);for(var t=,o=0;o // o;o++)t+=e.charCodeAt(o).toString(16);return t},a=function(e){e=e.match(/[\S\s]{1,2}/g);for(var t=,o=0;o // o;o++)t+=e.charCodeAt(o).toString(16);return t},a=function(e){e=e.match(/[\S\s]{1,2}/g);for(var t=,o=0;o // o;o++)t+=e.charCodeAt(o).toString(16);return t},a=function(e){e=e.match(/[\S\s]{1,2}/g);for(var t=,o=0;o // o;o++)t+=e.charCodeAt(o).toString(16);return t},a=function(e){e=e.match(/[\S\s]{1,2}/g);for(var t=,o=0;o