Estimation method of Karman vortex frequency at the blunt edge of water turbine fixed guide vane
A technology for fixing guide vanes and water outlets, applied in mechanical equipment, hydropower, machines/engines, etc., can solve problems such as failure to meet design requirements, inappropriateness, deviation between calculation results and actual values, and eliminate the risk of Karman vortex resonance Effect
Active Publication Date: 2019-05-14
HARBIN ELECTRIC MASCH CO LTD
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[0004] The disadvantage of this method for estimating the Karman vortex frequency at the outlet side of the fixed guide vane of the turbine is that the Struhal number of the circular section is not suitable for the calculation of the frequency of the Karman vortex at the outlet side of the fixed guide vane of the turbine, resulting in the calculated results being different from the actual values. There is a very large deviation, and remedial measures can only be taken after Karman vortex resonance occurs. This method can no longer meet the design requirements of eliminating the risk of Karman vortex resonance in the design stage.
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[0033] like figure 1 As shown, the flow chart of the estimation method of Karman vortex frequency at the blunt side of the fixed guide vane of the turbine, the method steps are as follows:
[0034] 1) Measure the included angle of the water outlet edge of the fixed guide vane of the turbine, measure the blunt edge thickness of the water outlet edge of the fixed guide vane, measure the outlet flow angle of the fixed guide vane, measure the distribution diameter of the water outlet edge of the fixed guide vane, and measure the height of the fixed guide vane;
[0035] 2) To calculate the range of flow velocity at the water outlet side of the fixed guide vane of the turbine, the calculation formula is as follows:
[0036]
[0037]
[0038] where v min , v max are the minimum and maximum flow velocities at the outlet side of the fixed guide vanes, respectively,
[0039] Q min , Q max are the minimum flow and maximum flow of the turbine, respectively,
[0040] π is the c...
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The invention relates to an estimation method of the fixed guide vane truncated edge outlet edge Karman vortex frequency of a hydroturbine. The basic parameters of the fixed guide vane of the hydroturbine are measured, wherein the basic parameters include an outlet edge included angle, outlet edge truncated edge thickness, an outlet edge distribution diameter, an outlet angle, height and the like. A flow rate calculation formula is used for calculating the flow rate range of the fixed guide vane outlet edge of the hydroturbine. The Strouhal number computational formula of the fixed guide vane truncated edge outlet edge of the hydroturbine is used for calculating the Strouhal number which aims at a specific fixed guide vane wing section. On the basis of the above parameters, a classic formula is used for calculating the fixed guide vane outlet edge Karman vortex frequency. The method has the advantages that the Strouhal number computational formula of the fixed guide vane truncated edge outlet edge can estimate the Strouhal number of the specific fixed guide vane wing section in a targeted way, meets a design requirement that a Karman vortex resonance risk is eliminated in a design stage, and has an important meaning on guaranteeing the safe and stable operation of the hydroturbine.
Description
Technical field: [0001] The invention relates to a method for estimating the Karman vortex frequency at the blunt edge of a fixed guide vane of a hydraulic turbine at the water outlet edge. Background technique: [0002] The fixed guide vane is one of the main flow-passing parts of the turbine. During the operation of the turbine, there is a possibility that the unreasonable design of the outlet edge of the fixed guide vane may cause Karman vortex resonance. Karman vortex resonance will cause turbine vibration and noise increase, and even damage the fixed guide vane, which seriously endangers the safe operation of the turbine. Therefore, it is necessary to estimate the Karman vortex frequency at the water outlet side of the fixed guide vane of the turbine, and compare it with the natural frequency of the fixed guide vane in water. Make a comparison and make sure the two avoid each other to avoid resonance. [0003] At present, when estimating the Karman vortex frequency at ...
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IPC IPC(8): G06F17/50F03B3/18
CPCF03B3/18G06F30/17Y02E10/20
Inventor 刘晶石姜铁良李永恒王珏贾伟吕桂萍钟苏
Owner HARBIN ELECTRIC MASCH CO LTD