The study is aimed at quantifying the relative contribution of key heat transfer modes in lyophilization. Measurements of vial heat transfer rates in a laboratory-scale freeze-dryer were performed using pure water, which was partially sublimed under various conditions. The separation distance between the shelf and the vial was systematically varied, and sublimation rates were determined gravime...

an investigation has been carried out on the temperature of a biscuit on the cooling line of razavi food industries company. for thispurpose, the time variations of biscuit’s top surface temperature in traveling from oven to packing station on the conveyor packing station by conveyors has been studied. the fourier field equation for transient heat transfer is used as the basis for the determini...

An ongoing program at the National Institute of Standards and Technology (NIST) is aimed at improving and standardizing heat-flux sensor calibration methods. The current calibration needs of U.S. science and industry exceed the current NIST capability of 40 kW/m2 irradiance. In achieving this goal, as well as meeting lower-level non-radiative heat flux calibration needs of science and industry,...

Improved Finite-Volume Method for Radiative Hydrodynamics Alan Wray* Corresponding author: [email protected] * NASA Ames Research Center, USA Abstract: Fully coupled simulations of hydrodynamics and radiative transfer are essential to a number of fields ranging from astrophysics to engineering applications. Of particular interest in this work are hypersonic atmospheric entries and associate...

We derive shape-independent limits to the spectral radiative heat-transfer rate between two closely spaced bodies, generalizing the concept of a black body to the case of near-field energy transfer. Through conservation of energy and reciprocity, we show that each body of susceptibility χ can emit and absorb radiation at enhanced rates bounded by |χ|/ Imχ, optimally mediated by near-field photo...

The convergence of heat below subsidence inversions was estimated from radiosonde ascents on fine summer days. Sensible heat input from the ground was estimated from measurements of heat fluxes and net radiation over a wheat field. Absorption and back scattering of solar radiation by aerosol throughout the atmosphere were calculated from measurements of solar radiation at the ground. Radiation ...

Abstract An exact analysis of heat transfer accompanied by mass transfer flow of a Casson fluid past an exponentially accelerated infinite vertical plate with Newtonian heating in the presence of radiation is presented here. The governing coupled linear partial differential equations are transformed into linear ordinary differential equations by using non-dimensional variables. The resulting eq...

In this study, by using the finite volume method, the heat transfer in a convective straight fin with temperature-dependent thermal properties and an internal heat generation under multi-boiling heat transfer modes are analyzed. In this regard, the local heat transfer coefficient is considered to vary within a power-law function of temperature. In the present study, the coexistence of all the b...

the performance of a γ-al 2 o 3 /n-decane nanofluid shell-and-tube heat exchanger in a biomass heating plant is analyzed to specify the optimum condition based on the maximum heat transfer rate and performance index for wide range of nanoparticle volume fraction (0–7%). compared with pure          n-decane, the obtained results in this research show that by using γ-al 2 o 3 /n-decane nanofluid ...