Prismatic cavity blade tip for controlling leakage flow of movable blade tip of turbine

Abstract

The invention provides a prismatic cavity blade tip for controlling leakage flow of a movable blade tip of a turbine. At the blade tip of a movable blade of the turbine, a plurality of prismatic cavities are formed from the front edge to the tail edge of the movable blade of the turbine; and the ratio of the maximal depth h of the prismatic cavities to the height H of the movable blade of the turbine is 0.5%-4%. According to the prismatic cavity blade tip for controlling the leakage flow of the movable blade tip of the turbine provided by the invention, a part of leaking fluid which enters a clearance enters the prismatic cavities to form vortex in a rolling way; at one hand, the dynamic energy of the fluid in the clearance is dissipated; on the other hand, a jet flow stop effect is achieved on the fluid in the clearance above the cavities; and thus the aim of controlling the leakage flow of the blade tip of the turbine is realized; the leakage amount of the blade tip of the turbine isreduced; the size and strength of leakage vortex of the blade tip are reduced; leakage related loss of the turbine is reduced; the efficiency of the turbine is improved; and furthermore the prismaticcavity structure can reduce the weight of the blade of the turbine.

Description

technical field [0001] The invention belongs to the field of turbines, and in particular relates to a prismatic concave-cavity blade top for controlling the leakage flow of the blade tip of a turbine blade. Background technique [0002] As one of the key power components of the engine, the turbine is the key content in the engine design. The main research content of improving the performance of the turbine is to control the internal flow of the turbine to reduce the loss of the turbine and increase the power of the turbine. Turbine blade tip clearance leakage flow is one of the typical flows inside the turbine, which not only reduces the load on the blade tip, but also creates a complex vortex system that makes the flow in the end region more complicated. Studies have shown that the loss caused by the gap leakage flow in the end region of the turbine cascade is as high as the end region. 87% of the district's total losses. Especially in recent years, high-performance turbi...

AI Technical Summary

Problems solved by technology

The most direct and effective way to control the gap flow is to reduce the gap value, but in order to avoid collision, contact and even damage to the components between the rotor blade and the casing, a reasonable gap value must be considered in the turbine design

The gap flow passive control technology widely studied now mainly includes tip / casing trimming, tip shroud, winglet, tip rib / groove, modern sealing structure, etc. Most of the research focuses on ensuring a certain gap value Effective measures should be taken to control the leakage flow, and the control effects of various gap flow control technologies will vary with specific objects, and there are corresponding deficiencies. Currently, the actual application of the technology is still limited.

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