Search results
Results From The WOW.Com Content Network
The vortex tube, also known as the Ranque-Hilsch vortex tube, is a mechanical device that separates a compressed gas into hot and cold streams. The gas emerging from the hot end can reach temperatures of 200 °C (390 °F), and the gas emerging from the cold end can reach −50 °C (−60 °F). [ 1 ]
More simply, vortex lines move with the fluid. Also vortex lines and tubes must appear as a closed loop, extend to infinity or start/end at solid boundaries. Fluid elements initially free of vorticity remain free of vorticity. Helmholtz's theorems have application in understanding: Generation of lift on an airfoil; Starting vortex; Horseshoe vortex
A vortex tube is the surface in the continuum formed by all vortex lines passing through a given (reducible) closed curve in the continuum. The 'strength' of a vortex tube (also called vortex flux ) [ 10 ] is the integral of the vorticity across a cross-section of the tube, and is the same everywhere along the tube (because vorticity has zero ...
The first source term on the right hand side represents vortex stretching. The equation is valid in the absence of any concentrated torques and line forces for a compressible , Newtonian fluid . In the case of incompressible flow (i.e., low Mach number ) and isotropic fluids, with conservative body forces, the equation simplifies to the ...
Georges-Joseph Ranque (7 February 1898 – 15 January 1973) was the inventor of the Ranque-Hilsch vortex tube, which generates streams of hot and cold gas from a stream of compressed gas. Georges-Joseph Ranque was born in Ambérieu-en-Bugey , France in 1898. [ 1 ]
The tube tapers to a small exit aperture at one or both ends. This tangential injection of gas results in a spiral or vortex motion within the tube, and two gas streams are withdrawn at opposite ends of the vortex tube; centrifugal force providing the isotopic separation. The spiral swirling flow decays downstream of the feed inlet due to ...
In general, the evolution of vorticity can be broken into contributions from advection (as vortex tubes move with the flow), stretching and twisting (as vortex tubes are pulled or twisted by the flow) and baroclinic vorticity generation, which occurs whenever there is a density gradient along surfaces of constant pressure.
The general form for the Reynolds number flowing through a tube of radius r (or diameter d): = = where v is the velocity of the fluid, ρ is its density, r is the radius of the tube, and μ is the dynamic viscosity of the fluid. A turbulent flow in a fluid is defined by the critical Reynolds number, for a closed pipe this works out to approximately