For further study of the similarity law of fluctuating pressure, a series of model tests with more scales, covering a wide range of Reynolds number and Froude number have been completed. The data of the fluctuating pr...For further study of the similarity law of fluctuating pressure, a series of model tests with more scales, covering a wide range of Reynolds number and Froude number have been completed. The data of the fluctuating pressure acting the floor level within 2-D free hydraulic jump were obtained. Froude number varied from 2.94 to 8.61, and Reynolds number ranged from 2×104 to 6×105. The tests were conducted in a glass flume with 0.2 m in width and six fluctuating pressure probes (Type CYG-01) were installed on the floor within the jump. Experimental results indicate that the amplitude scale of fluctuating pressure is the length of the model, i.e., Pr=Lr, which agrees with gravity similarity law. The frequency scale of the fluctuating pressure is an unity i.e., fr=1, which does not satisfy the gravity similarity law.展开更多
Taking account of turbulence intensity, non-uniformity of velocity distribution at the initial and sequent section of hydraulic jump and frictional drag on the floor within jump range, this paper derives new formulas ...Taking account of turbulence intensity, non-uniformity of velocity distribution at the initial and sequent section of hydraulic jump and frictional drag on the floor within jump range, this paper derives new formulas for calculating the ratio of conjugate depths and the efficiency of energy dissipation in the two-dimensional free hydraulic jump. It has been verified by test data that the new formulas are not only exact in theory but also still better in conformity with practice.展开更多
The pressure fluctuation amplitude is very important for the load design of structures and to research flow cavitation, using 182 sample records of fluctuation pressure obtained from model tests and prototype observat...The pressure fluctuation amplitude is very important for the load design of structures and to research flow cavitation, using 182 sample records of fluctuation pressure obtained from model tests and prototype observations for many kinds of outlet works,this paper studies statistical characteristics of fluctuating pressure amplitude in outlet works. The results indicate that the probability of fluctuating pressure amplitude in outlet works obeys Gaussian normal distribution,and the verification of prototype observation data from Gezhouba project further proves that the conclusion is true.展开更多
文摘For further study of the similarity law of fluctuating pressure, a series of model tests with more scales, covering a wide range of Reynolds number and Froude number have been completed. The data of the fluctuating pressure acting the floor level within 2-D free hydraulic jump were obtained. Froude number varied from 2.94 to 8.61, and Reynolds number ranged from 2×104 to 6×105. The tests were conducted in a glass flume with 0.2 m in width and six fluctuating pressure probes (Type CYG-01) were installed on the floor within the jump. Experimental results indicate that the amplitude scale of fluctuating pressure is the length of the model, i.e., Pr=Lr, which agrees with gravity similarity law. The frequency scale of the fluctuating pressure is an unity i.e., fr=1, which does not satisfy the gravity similarity law.
文摘Taking account of turbulence intensity, non-uniformity of velocity distribution at the initial and sequent section of hydraulic jump and frictional drag on the floor within jump range, this paper derives new formulas for calculating the ratio of conjugate depths and the efficiency of energy dissipation in the two-dimensional free hydraulic jump. It has been verified by test data that the new formulas are not only exact in theory but also still better in conformity with practice.
文摘The pressure fluctuation amplitude is very important for the load design of structures and to research flow cavitation, using 182 sample records of fluctuation pressure obtained from model tests and prototype observations for many kinds of outlet works,this paper studies statistical characteristics of fluctuating pressure amplitude in outlet works. The results indicate that the probability of fluctuating pressure amplitude in outlet works obeys Gaussian normal distribution,and the verification of prototype observation data from Gezhouba project further proves that the conclusion is true.
