| Lock culvert valves are one of the important equipments which control the navigation lock's performance. The valves open and close frequently under unsteady flow all year round with adverse environments and complicated conditions. One of the key issue for the study of the lock culvert valves is the cavitation characteristics and its preventive and corrective measures, the other one is the valve's hoist load and its pulsation amplitude. The former concerns whether the valves operate normally, and the latter is not only related to the capability of headstock gear and valve structure, but also related to the reliability and flexibility of valve's operation.On the basis of analyzing and studying on the former test results of hoist load of reverse tainter valve which is the main type of valves for navigation locks, a large scale (1:16) physical model for YinPan lock culvert valve has been built. Through the steady and unsteady flow experiments, structure of the acting flow on the valve has been observed and analyzed in detail. It has been found that the valve's net hydrodynamic hoist load can be composed of two parts, one is the acting force result from water in culvert and the other result from the descending and rising flow in valve well. Furtherly the formula of the net hydrodynamic hoist load has been put forward by theoretic analysis, and the calculation results has been proved to be agreed well with the experimental results. Meanwhile, the factors affecting the net hydrodynamic hoist load and their changing laws have been further studied. The further research direction is also been pointed out.Reverse tainter valve is used most widely in high head navigation locks, research results of this paper can not only provide important parameters and theoretic supporting for design and calculation of valve's structure and hoist system in high head navigation locks, but also can be applied to the revision of relevant standards.
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