Method for judging flow state of throat-type energy dissipater

Abstract

The invention discloses a method for judging a flow state of a throat-type energy dissipater, which comprises the following steps of: acquiring the diameter d of an energy dissipater hole, the diameter D of a flood discharge hole and the thickness T of the energy dissipater, and calculating an aperture ratio beta and a dimensionless thickness alpha, wherein the aperture ratio beta is the ratio of the diameter d of the energy dissipater hole to the diameter D of the flood discharge hole, namely, beta=d / D, and the dimensionless thickness alpha is the ratio of the thickness T of the energy dissipater to the diameter D of the flood discharge hole, namely, alpha=T / S; acquiring a hydraulic parameter Damkohler number Re, namely, Re=vD / (mu / p), wherein v is the speed of an incoming flow, mu is the dynamic viscosity of water and p is the density of the water; calculating a critical thickness alpha(c) according to the following formula: alpha(c)=(3.33beta4-8.01beta3+7.02beta2-2.68beta+0.39)*10-6Re-46.42beta4+110.52beta3-97.20beta2+37.41beta-4.94; comparing the critical thickness alpha(c) with the dimensionless thickness alpha; when alpha is greater than alpha(c), judging the throat-type energy dissipater is in a plugging flow state; when alpha is equal to alpha(c), judging the throat-type energy dissipater is in a critical flow state; and when alpha is less than alpha(c), judging the throat-type energy dissipater is in an orifice flow state.

Description

technical field [0001] The invention relates to a method for discriminating the flow state of a sudden contraction and expansion type energy dissipator in a flood discharge tunnel of a water conservancy and hydropower project, which is mainly used to discriminate the internal flow of the energy dissipator under different structural shapes and different flow conditions. What is presented is the flow state of plug flow or orifice flow. Background technique [0002] In the high dam project, in order to eliminate the huge energy of the discharge water flow in the reservoir area and realize the connection between the reservoir area and the upstream and downstream water flow of the downstream river, the discharge structures need to adopt effective energy dissipation devices. Traditional energy dissipation methods include bottom flow energy dissipation, deflecting flow energy dissipation and surface flow (or bucket flow) energy dissipation, etc. These energy dissipation methods hav...

AI Technical Summary

Problems solved by technology

Under such circumstances, it is important to distinguish the flow state of the sudden-contraction-sudden-expansion energy dissipation device under certain working conditions, that is, the flow state of plug flow or orifice flow. At present, There is a lack of an effective method for discriminating the flow state of sudden contraction and expansion energy dissipators

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