Jet Flow Development Research Articles

Numerical Simulation of an Axisymmetric Flow in a Poppet Valve for Oil Hydraulics Using the Vortex Method.

In the present study, numerical simulations of the three-dimensional axisymmetric flow in a poppet valve for oil hydraulics are conducted using the vortex method. The fluids are assumed to be inviscid and incompressible. The vibration of the poppet occurs in the axial direction because the poppet is supported by a spring and a dashpot. Pulsating flow rates from a swash plate piston pump are employed as a boundary condition for comparison with experimental results and sinusoidal flow rates are also used as a boundary condition to investigate the effects of the frequency and the amplitude of the flow rate on the valve lift and flow in the valve. The process of jet flow development, the fluctuations of the valve lift and the velocity distributions in the valve are investigated for the vibrating poppet.

Numerical simulation of an unsteady axisymmetric flow in a poppet valve using a vortex method

In the present study, numerical simulations of the flow in a three-dimensional axisymmetric poppet valve are conducted using a vortex method. The fluids are assumed inviscid and incompressible. The vibration of the poppet, supported by a spring and a dash pot, occurs in the axial direction in some range of parameters. The numerical simulations are carried out by varying systematically the parameters of the calculation, namely the supply pressure, the spring constant, the mass of the poppet and the conical angle of the poppet. The process of jet flow development, the fluctuations of the valve lift and the velocity distributions in the valve are investigated for the poppet vibrating.

Numerical and experimental flow visualization of unsteady flow in a spool valve

In the present study, the numerical and experimental flow visualization of the jet fl ow issuing from the orifice for repeated spool valve opening and closing are conducted. The discrete-vortex method is employed as the numerical simulation. A two-dimensional model of the spool valve is designed to visualize the jet flow using the hydrogen bubble method. A digital image- processing technique for the image obtained by a CCD camera is employed. The computational results and the experimental ones are compared, and jet angles and the process of jet flow development are considered.

Closure to “Discussion of ‘Plane Turbulent Wall Jet Flow Development and Friction Factor’” (1963, ASME J. Basic Eng., 85, pp. 53–54)

Closure to “Discussion of ‘Plane Turbulent Wall Jet Flow Development and Friction Factor’” (1963, ASME J. Basic Eng., 85, pp. 53–54)