首页|Investigation on the choked mass-flow characteristics of the helium fluid during the Joule-Thomson process in micro-orifice under different high pressures
Investigation on the choked mass-flow characteristics of the helium fluid during the Joule-Thomson process in micro-orifice under different high pressures
扫码查看
点击上方二维码区域，可以放大扫码查看
原文链接
NSTL
Elsevier
The micro-orifices during the Joule-Thomson process are used in a variety of energy applications such as microfluidic systems and large-scale cryogenic helium systems。 The structure of the micro-orifice impacts the cooling capacity by adapting the mass flow rate and pressure drop in the refrigeration system。 The pressure drops and flow characteristics in micro-orifices with diameters of 20-40 mu m and thicknesses of 50 mu m were numerically and experimentally investigated。 Helium was used as the working fluid， and the simulations using CFD (Computational Fluid Dynamics) method were conducted with upstream pressure (pu) of 0。5-2。0 MPa (MegaPascal) and downstream pressure (pd) of 0。1-1。5 MPa at 293 K (Kelvin)。 The simulations found that the completely choked pressure ratio of each micro-orifice is smaller than the theoretical critical pressure ratio lambda*=0。487 and revealed the flow field characteristics in micro-orifices flow under different working conditions。 Experiments were carried out with four micro-orifices with the thickness of 50 mu m and the effective diameter of 23。88 mu m， 26。53 mu m， 33。30 mu m， 40。69 mu m under different pressure conditions (pu 0。5-2。0 MPa， pd 0。1-1。5 MPa)， respectively。 The errors between the numerical and experimental mass flow rates in different micro-orifices corresponding to the pressures are within 10 %。 The W。 B。 Brower model was used to predict the mass flow rates that are consistent with the experiments and simulations。 The semi-empirical model is developed using the data set for the modifications to W。 B。 Brower model and with an error range of +/- 0。08 mg/s in the calculated flow rate compared to the experimental value。
NSTL
Elsevier
