Review of Ranque–Hilsch vortex tube experiments using air

Heat pump model for Ranque–Hilsch vortex tubes

“…Vortex tubes can vary substantially in their geometry and their performance [11,14,15], but we would like at least some very rough estimates. a is relatively straightforward to estimate, since it follows directly from measurements of the radial pressure profile.…”

“…Behera et al found that the simulations with smaller cold end diameters more closely matched the model put forth by Ahlborn et al, but that the simulations with larger cold end diameters did not closely match that model and had substantially larger temperature separations. In general, computational studies have played an important role in vortex tube research, addressing a wide variety of issues involving vortex tube flow and temperature separation [11][12][13][14][15].…”

Detailed thermodynamics for analysis and design of Ranque‐Hilsch vortex tubes

“…It was first reported by Ranque in 1933 and next reported in detail by Hilsch in 1946 and verified by Johnson in 1947. Some reviews describe extensive studies of the phenomena, devices, and applications; that of Eiamsa‐ard and Promvonge is particularly thorough. Of particular note are the experimental temperature separation results for ambient to moderate pressure pure gases, subatmospheric pressure gases, natural gas, steam, liquids, vapor‐liquid propane, and for mixtures .…”

“…There have also been measurements of conditions within the tube, computational simulations, and thermodynamic analyses . Although industrial applications for cooling with the vortex tube have been suggested for this simple nonmechanical alternative to refrigeration systems, and commercial devices have been patented and marketed, since its energy efficiency is quite low, it is probably only a “niche” cooling device for “small‐scale, spot‐cooling applications.” Lewins and Bejan analyze the thermodynamics of options for a full refrigeration process. Mohammadi and Farhadi compare results for a cascade of vortex tubes with a distillation column for separating hydrocarbon mixtures, concluding that the small capital costs for the vortex tubes make such a system “advantageous.” Williams presents results for the total cooling and heating capacities by the outlet streams since both flow and temperature change with conditions.…”

“…It is generally agreed there is a complex structure of vortices both close to the tube wall that contains the hotter fluid elements, and close to the tube center, where the cooler fluid flows in the opposite direction, with energy exchange between these elements yielding the thermal separation . Yet, the precise mechanisms still seem not to be fully understood and prediction of the behavior is challenging …”