Influence of Inter-row Gap Value on Turbine Losses

[摘要] This paper presents the results of a numerical investigation of the gap influence on the turbine efficiency. The rotor-stator interaction in a (1/2)-stage turbine is simulated bysolving the quasi-three-dimensional unsteady Euler/Navier-Stokes equations using aparallelized numerical algorithm. The reduced turnaround time and cost/MFLOP ofthe parallel code was crucial to complete the numerous run cases presented in thispaper. The inter-row gap effect is evaluated for 4 gaps, 3 radial positions and 3 angularvelocities. As expected, the results presented in this paper show that the efficiencyincreases and losses decrease while the gap size increases. The maximum efficiencylocation, however, corresponds to values of the gap size which may be too large forpractical use (approximately inch). Fortunately, a local maximum efficiency andminimum losses location has been found at approximately 0.5 inches gap size. Theefficiency variation near the local optimum is large, in some configurations being as highas 1.4 points for a gap size variation of only 0.076 inches. Data produced by thenumerical simulations can be used to develop a design rule based on the inter-row gapsize.

[学科分类] 力学，机械学