In the design of heat exchangers, it is necessary to determine the heat transfer rate between hot and cold fluids in order to calculate the overall heat transfer coefficient and the heat exchanger efficiency. Heat transfer rate can be determined by inverse methods. In this study, the unknown space-time dependent heat flux imposed on the wall of a heat exchanger internal tube is estimated by app...

in this paper, the conjugate gradient method coupled with adjoint problem is used in order to solve the inverse heat conduction problem and estimation of the time- dependent heat flux using the temperature distribution at a point in a three layer system with none homogeneous boundary conditions. also, the effect of noisy data on final solution is studied. for solving this problem the general co...

this paper presents a hybrid technique for simultaneous estimation of parameter and function in inverse heat conduction problems. no prior information is used for the functional form of the heat flux in the present study. the scheme presented here is a combination of two different classical methods: the variable metric method (vmm) and gauss method (gm). the determination of the unknown thermal...

metric (mapping evapotranspiration at high resolution with internalized calibration) is known as an appropriate surface energy balance model for the estimation of the spatial distribution of evapotranspiration (et) in semi-arid regions. based on lysimeter measurements, metric has shown et estimates of 10% on a sub-field scale on a daily basis. there is a need to identify how the model is sensit...

Surface heat flux estimation using temperature measurement data from the interior points is known as inverse heat conduction problem (IHCP). Several methods have been developed as solution techniques for IHCP’s including analytical and numerical approaches. Digital filter representation for IHCP solution (Woodbury and Beck, 2013; Beck et al., 1985) is one of the methods which can be used for ne...

[1] Traditionally, analytical solutions for heat transport in soils have been used in combination with heat pulse probe (HPP) measurements to estimate soil thermal properties. Although the analytical method has resulted in accurate estimation of soil thermal properties, we suggest that parameter estimation using inverse modeling (IM) provides new and unique opportunities for soil thermal charac...

Heat transfer coefficient in nucleate pool boiling near critical heat flux at least one orderhigher than the convectional heat transfer modes. In this paper, an experimental setup isdesigned and fabricated to investigate the mechanism of heat transfer from boiling surface tobulk liquid near critical heat flux. The images of pool boiling near the high heat flux regionreveals that the individual ...

sometimes the need for non-circular ducts arises in many heat transfer applications because of lower pressure drop of non-circular cross section such as square duct compared to circular tube, particularly in compact heat. but square cross section has poor heat transfer performance and it is expected that using a nanofluid as a new heat transfer media may improve the heat transfer performance of...

This paper presents a method for the estimation of the soil heat flux that was used to determine the evapotranspiration in ecosystems. The great advantage of this approach is that there is the possibility to use this method for both daytime and nighttime as well as that the parameters are adaptively recalculated depending on three soil temperatures. It enables the estimation in situ of the soil...