Experiments on the flow characteristics of hydraulic orifices under high or low temperature conditions

Abstract

A new test rig with a compact experimental module has been developed in this study to support experiments on fluid mechanics of hydraulic orifices under high or low temperature conditions, by using the test rig, experiments on flow characteristics of a sharp-edged orifice and a thick-wall orifice were conducted in a temperature range of -10°C∼+80°C. Experimental results show that in a wide temperature range, the Flow-Pressure characteristics of the sharp-edged orifice are not sensitive to temperature changes, but that of the thick-wall orifice will vary obviously at different temperatures; In the temperature range up to 20°C, the Discharge coefficients and Damping forces of both of the two orifices remain at constants, however, when the fluid temperature is below 20°C, Discharge coefficients of the two orifice will drop linearly, damping forces of the two orifice will increase, but discharge coefficient and damping force of the thick-wall orifice will respectively drop and increase more sharply than that of the sharp-edged orifice, so this indicates that at low temperature conditions the fluid resistance and energy loss when it passes through a thick-wall orifice are larger than that when it passes through a sharp-edged orifice.