Optimized Design of a Plate Stiffener for Steam Turbine Exhaust Hood

An optimization was conducted to the design of a plate stiffener located in the lower area of steam turbine exhaust hood using Latin hypercube experiment design, cubic response surface model and Hooke-Jeeves direct search technique. Based on numerical investigation of a large number of samples, the influence of different geometric parameters of the stiffener was studied on the aerodynamic performance of the exhaust hood, which was examined under variable conditions after optimization. Results show that both the distance between the stiffener and the meridian plane X as well as the dip angle of the stiffener θ have large influence on the aerodynamic performance of the exhaust hood, while the distance between the stiffener bottom and the hood outlet Y as well as the length of the stiffener L have little influence. The static pressure recovery coefficient can be improved effectively by arranging the stiffener appropriately, when the outlet non-uniformity would be reduced; however, this may lead to a certain loss of the total pressure.