In present study, the two phase flow boiling heat transfer coefficient and pressure drop of R410A, R32 and R290 in microchannels are demonstrated. The experimental data were conducted in horizontal stainless steel tubes with the inner diameter of 0.3 mm and 1.5 mm. The testing conditions were performed with the mass fluxes range from 200 to 500 kg/m2s, the heat fluxes from 10 to 20 kW/m2, the s...

cooling towers are widely used in most industrial units to reject waste heat to the atmosphere. this paper deals with an experimental analysis of heat and mass transfer phenomena between water and air by direct contact in a cooling tower. the tower is filled with 6 type packing. in this study temperature and pressure drop and tower characteristics was used in determining experimentally the ther...

Title of Document Application of Plate Heat Exchanger for Low Temperature Lift Heat Pump Systems Song Li, Master of Science, 2012 Advisor Professor Reinhard Radermacher, Department of Mechanical Engineering In this thesis I investigated the energy saving potential of a low temperature lift heat pump (LTLHP) such as water source heat pump (WSHP), and studied the utilization of a plate heat excha...

A lattice Boltzmann model is proposed to asses the impact of variable molecular transport effects on the heat and mass transfer in a horizontal shallow cavity due to natural convection. The formulation includes a generalized form of the Soret and Dufour mass and heat diffusion (cross diffusion) vectors derived from non-equilibrium thermodynamics and fluctuation theory. Both the individual cross...

abstract: in this paper, a new population-based search called the bees algorithm (ba) is presented to estimate the time-dependent heat transfer coefficient and the corresponding heat flux at the boundaries of a two-dimensional body subjected to transient heat conduction, using the temperature measurements at discrete nodal locations on the boundaries, where heat flux is specified as the boundar...

The performance of a single spray for electronic power devices using deionized (DI) water and pure silver (Ag) particles as well as multi-walled carbon nanotube (MCNT) particles, respectively, is studied herein. The tests are performed with a flat horizontal heated surface using a nozzle diameter of 0.5 mm with a definite nozzle-to-target surface distance of 25 mm. The effects of nanoparticle v...

Modeling mass-transfer across the sediment-water interface is a significant issue in environmental hydraulics. In fact diffusional exchanges of solutes between the bed sediment and the overlying water column could greatly affect water quality. Particularly, diffusional flux of dissolved oxygen (DO) towards the bed sediments from the water column could be responsible for low and unacceptable lev...

In this paper we discuss the effect of chemical reaction and thermal radiation on unsteady free convective heat and mass transfer flow through a porous medium in a vertical wavy channel. The unsteadiness in the flow is due to the oscillatory flux in the flow region. The coupled equations governing the flow, heat and mass transfer have been solved by using a perturbation technique with the slope...

We report recent Chandra observations of the ULX in the elliptical galaxy NGC 3379 that clearly detect two flux variability cycles. Comparing these data with the Chandra observation of 5 years ago, we measure a flux modulation with a period of 12.6 hr. Moreover, we find that the emission undergoes a correlated spectral modulation, becoming softer at low flux. We argue that our results establish...