Flow boiling heat transfer with the refrigerants R-134a and R-245fa in copper microchannel cold plate evaporators is investigated. Arrays of microchannels of hydraulic diameter 1.09 mm and 0.54 mm are considered. The aspect ratio of the rectangular cross section of the channels in both test sections is 2.5. The heat transfer coefficient is measured as a function of local thermodynamic vapor qua...

Water tunnel experiments have been performed to examine how large scale, high intensity freestream turbulence affects heat transfer through a laminar flat plate boundary layer. Time-Resolved Digital Particle Image Velocimetry (TRDPIV) was used to examine the flow field along with timeresolved heat transfer from the wall. The surface heat flux was measured with a newly developed thin-film sensor...

This paper presents the results of modelling the heat transfer process in heterogeneous media with the assumption that part of the heat flux is dispersed in the air around the beam. The heat transfer process in a solid material (beam) can be described by an integer order partial differential equation. However, in heterogeneous media, it can be described by a sub- or hyperdiffusion equation whic...

Parallel heat flux in a steady-state SOL is determined via fully kinetic simulations using the 1d3v particle-in-cell code PARASOL. In order to better evaluate the heat load on the divertor plates, the ion and electron velocity distributions functions (VDF), heat flux, and heat flux limiters αi and αe are calculated. The effects of collisionality, recycling rate, ion-electron mass ratio, and sou...

Applying properties of the Laplace transform, the transient heat diffusion equation can be transformed into a fractional (extraordinary) differential equation. This equation can then be modified, using the Fourier Law, into a unique expression relating the local value of the time-varying temperature (or heat flux) and the corresponding transient heat flux (or temperature). We demonstrate that t...

We use polarity reversal systematics from numerical dynamos to quantify the hypothesis that the modulation of geomagnetic reversal frequency, including geomagnetic superchrons, results from changes in core heat flux related to growth and partial collapse of the two seismically-imaged lower mantle superplumes. We parameterize the reversal frequency sensitivity from numerical dynamos in terms of ...

Alcator C-Mod was recently upgraded with multiple diagnostics to measure the heat flux footprint on the outer divertor: IR thermography, plasma conditions from Langmuir probes (LPs), and embedded calorimeters to measure local energy deposition. In addition to providing consistency checks of the inferred heat flux profiles, these measurements allow an assessment of the local sheath heat flux tra...

A lumped heat transfer model and parameter estimation technique are proposed for determining key parameters associated with a heat flux Differential Scanning Calorimeter (DSC). Part I of this two-part paper focuses on developing the mathematical model and describing the proposed parameter estimation technique. Part II presents the numerical implementation using a conventional Runge-Kutta method...

Recent advances in heat flux measurement have resulted in the development of a robust thermopile heat flux sensor intended for use in extreme thermal environments. The High Temperature Heat Flux Sensor (HTHFS) is capable of simultaneously measuring thermopile surface temperature and heat flux at sensor temperatures up to 1000 ◦C. The need for high temperature heat flux calibration of the HTHFS ...

A theoretical analysis was carried out to investigate the characteristics of plasma arc injected transverse to a transverse-alternating magnetic field. Two mathematical models were developed to describe both the oscillating amplitude of the plasma arc root and the heat flux density distribution of plasma arc on the workpiece surface. The characteristic of plasma arc under the external transvers...