Book Description

It is cited that the designing of the exhaust duct profile, i.e., the selection of the shape of its meridian- and transfer-cross sections, is done in order to obtain minimal size, weight, hydraulic losses, and minimal nonuniformity in the gas velocity and gas pressure fields with the maximal diffusivity effect. The effect of improving the exhaust duct on the gas turbine's efficiency is shown by examining the gas flow processes in the turbine and exhaust duct simultaneously. The aerodynamic qualities of the exhaust duct were evaluated by blow-through tests using the duct itself or a model of it. The author discusses these tests at some length expressing the results in graph form. The author concludes that the hydraulic losses in the exhaust duct substantially affect the efficiency of a gas turbine; thus, the reduction of the hydraulic drag coefficient of the exhaust duct from 1.83 to 0.90 made it possible to raise the turbine's efficiency 4-5%. The author adds three other conclusions concerning reduction of hydraulic losses in the exhaust duct, the use of toric dividers in the radial-annular deflection region, and the smallest hydraulic drag coefficient obtained with an exhaust duct. (Author).