Heat flux gauges are one of the devices that are used to determine the heat loads to which high-speed aerospace structures are subjected during flight. Prior to installation, these gauges are calibrated. The calibration system must be well understood if the heat flux gauges are to provide useful data during flight tests. A pseudo three-dimensional model of the radiant heat flux gauge calibratio...

Two-phase heat transfer in microchannels can support very high heat fluxes for use in high-performance electronics-cooling applications. However, the effects of microchannel crosssectional dimensions on the heat transfer coefficient and pressure drop have not been investigated extensively. In the present work, experiments are conducted to investigate the local flow boiling heat transfer in micr...

This research presents temperature distribution and thermal strain of functionally graded material cylinders with varying thickness and temperature-dependency properties that are subjected to heat fluxes in their inner and outer layers. The heterogeneous distribution of properties is modeled as a power function. Using first-order temperature theory and the energy method, governing equations are...

International programmes such as EUROFLUX focus on the analysis of long-term fluxes and energy budgets in the biosphere. Reliable estimates of hourly energy budgets require an accurate estimation of soil heat flux, that is often non-negligible even in a forest, and can be predominant during the night. Over long periods of time such as one to several months, its contribution can also be signific...

Demand for high-performance cooling systems is one of the most challenging and virtual issues in the industry and Pulsating heat pipes are effective solutions for this concern. In the present study, the best predictor correlations of flow boiling and condensation are taken into account to model a single turn pulsating heat pipe mathematically. These considerations, result in derivation of more ...

DSMC simulation of re-entry of an object with shape and size close to that of ISRO’s Space Recovery Experiment (SRE) capsule has been analysed using the open-source tool dsmcFoam for three altitude conditions, viz. 85 km, 100 km and 115 km, and for three angles of attack, viz. 0, 20&40. The hypersonic free stream velocity of 8000 m/s and boundary surface temperature of 300 K have been used for ...

Experiments are conducted with a perfluorinated dielectric fluid, Fluorinert FC-77, to investigate the effects of channel size and mass flux (225–1420 kg/ms) on microchannel flow boiling regimes by means of high-speed photography. Seven different silicon test pieces with parallel microchannels of widths ranging from 100 to 5850 lm, all with a depth of 400 lm, are considered. Flow visualizations...

Fe3O4 nanofluid fully developed forced convection inside a copper tube is empirically investigated under the effect of a magnetic field. All of the investigations are performed under laminar flow regime (670≤Re≤1700) and thermal boundary conditions of the tube with uniform thermal flux. The tube is under the effect of a magnetic field in certain points. This research aims to study the effect of...

Transient phase change through a horizontal channel that subjected to discrete heat flux and filled with porous media of high-conductivity material, copper, is numerically investigated with n-pentane as the working fluid. The thermal non-equilibrium model is used in conjugate with the multiphase mixture model to analyze the transient behavior of fluid and solid phases. Three cases are studied r...