The vortex tube is an intriguing device that separates an incoming high-pressure fluid stream into a two low-pressure streams. Work interaction during the expansion process causes a temperature decrease in one of the two exit streams, while the other one experiences a temperature increase. The overall expansion process in a vortex tube therefore approaches isentropic rather than isenthalpic exp...

The vortex tube or Ranque–Hilsch vortex tube is a device that enables the separation of hot and cold air as compressed air flows tangentially into the vortex chamber through inlet nozzles. Separating cold and hot airs by using the principles of the vortex tube can be applied to industrial applications such as cooling equipment in CNC machines, refrigerators, cooling suits, heating processes, et...

The paper presents the analysis of the energy performance of an air vortex cooling tube under variations of the air inlet properties, with three independent experimental tests validated through the energy balance in the device. The experimental analysis includes the following variations of the input conditions: First, the effect of the air inlet pressure to the vortex tube, focused on the analy...

At low flow rate operation, Francis turbines feature a cavitating vortex rope in the draft tube resulting from the swirling flow of the runner outlet. The unsteady pressure field related to the precession of the vortex rope induces plane wave propagating in the entire hydraulic system. The frequency of the vortex rope precession being comprised between 0.2 and 0.4 times the turbine rotational s...

The low frequency noise from heat recovery steam generator (HRSG) makes dominant contribution to the noise on the boundary of plant, which generation mechanism is investigated in this presentation. The non-stationary flow field and aeroacoustic noise is studied with hybrid numerical simulation, which is comprised of CFD method based on Large Eddy Simulation (LES) and acoustic analogy by using F...

In this research, wave propagation analysis in polymeric smart nanocomposite micro-tubes reinforced by single-walled carbon nanotubes (SWCNT) conveying fluid is studied. The surrounded elastic medium is simulated by visco-Pasternak model while the composite micro-tube undergoes electro-magneto-mechanical fields. By means of micromechanics method, the constitutive structural coefficients of nano...

Large-scale computations of dynamically interacting vortex tubes forming filaments are performed with a view toward investigating their relationship to turbulent fluid flow. It is shown that the statistical properties of the tubes are consistent with commonly accepted observations about turbulence such as the Kolmogorov inertial range spectrum and lognormality of the vorticity distribution. A l...

During cross flow in a heat exchanger, heat transfer in the front portion of the tube is more compared to back portion of the tube. This is due to less formation of vortices at the backside of the tube. For uniform heat transfer to take place throughout the tube, it is necessary to increase the vortex formation at the rear side of the tube. The aim of this study is to explore the possibilities ...

Plasma based therapeutic products must undergo viral inactivation steps in order to minimize the risk of infection. Non-enveloped viruses such as hepatitis A and parvovirus are more recently being inactivated by using Ultra Violet light C (UV-C) irradiation techniques. A commonly used form of UV-C irradiation involves passing the protein solution through a helical tube that wraps around an irra...

Optical vortex trapping can allow the capture and manipulation of micro- and nanometre-sized objects such as damageable biological particles or particles with a refractive index lower than the surrounding material. However, the quest for nanometric optical vortex trapping that overcomes the diffraction limit remains. Here we demonstrate the first experimental implementation of low-power nano-op...