A one-dimensional heat transfer model for parallel-plate thermoacoustic heat exchangers

2014 ◽  
Vol 135 (3) ◽  
pp. 1149-1158 ◽  
Author(s):  
J. A. de Jong ◽  
Y. H. Wijnant ◽  
A. de Boer
Keyword(s):  
Heat Transfer ◽  
Heat Exchangers ◽  
Parallel Plate ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
One Dimensional

Transient Temperature Response of Variable Flow Heat Exchangers in a Marnoch Heat Engine

2014 ◽  
Vol 136 (11) ◽  
Author(s):  
P. Saneipoor ◽  
G. F. Naterer ◽  
I. Dincer
Keyword(s):  
Heat Transfer ◽  
Heat Exchangers ◽  
Heat Engine ◽  
Heat Transfer Model ◽  
Transient Temperature ◽  
Transfer Model ◽  
Gas Temperature ◽  
Variable Flow ◽  
Flow Heat ◽  
Shell And Tube

Within a Marnoch heat engine (MHE), a water/glycol mixture transfers heat from the heat source into a set of variable flow heat exchangers and removes heat from adjoining cold heat exchangers. The compressed dry air is used as the working medium in this heat engine. The MHE has four shell and tube heat exchangers, which operate transient and variable flow conditions. A new transient heat transfer model is developed to predict this transient behavior of the heat exchangers for different flow regimes and temperatures. The results from the model are validated against experimental results from an MHE prototype. The heat transfer model shows 85% agreement with measured data from the MHE prototype for the individual heat exchangers. This model can be used for similar shell and tube heat exchangers with straight or U-shaped tubes. The heat transfer model predicts the gas temperature on the shell side, when a step change is imposed on the liquid entering the tubes.

scholarly journals A one-dimensional modeling study on the effect of advanced insulation coatings on internal combustion engine efficiency

2020 ◽  
pp. 146808742092158
Author(s):  
Alberto Broatch ◽  
Pablo Olmeda ◽  
Xandra Margot ◽  
Josep Gomez-Soriano
Keyword(s):  
Heat Transfer ◽  
Combustion Engine ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Insulation Material ◽  
One Dimensional ◽  
Engine Efficiency ◽  
Dimensional Modeling ◽  
The One ◽  
The Impact

This article presents a study of the impact on engine efficiency of the heat loss reduction due to in-cylinder coating insulation. A numerical methodology based on one-dimensional heat transfer model is developed. Since there is no analytic solution for engines, the one-dimensional model was validated with the results of a simple “equivalent” problem, and then applied to different engine boundary conditions. Later on, the analysis of the effect of different coating properties on the heat transfer using the simplified one-dimensional heat transfer model is performed. After that, the model is coupled with a complete virtual engine that includes both thermodynamic and thermal modeling. Next, the thermal flows across the cylinder parts coated with the insulation material (piston and cylinder head) are predicted and the effect of the coating on engine indicated efficiency is analyzed in detail. The results show the gain limits, in terms of engine efficiency, that may be obtained with advanced coating solutions.

scholarly journals Numerical modelling of vertical borehole heat exchangers performance under Lithuanian Quaternary conditions

Baltica ◽  
2019 ◽  
Vol 31 (2) ◽  
pp. 146-153
Author(s):  
Audrius Indriulionis ◽  
Žygimantas Palaitis ◽  
Petras Šinkūnas ◽  
Robert Mokrik
Keyword(s):  
Heat Transfer ◽  
Numerical Model ◽  
Groundwater Flow ◽  
Heat Exchangers ◽  
Heat Transfer Model ◽  
Capital City ◽  
Transfer Model ◽  
Practical Tool ◽  
Borehole Heat Exchangers ◽  
Vertical Borehole

The vertical borehole heat exchangers were surrounded by the heterogeneous multilayered geological environment and groundwater flow that affected the performance of borehole plants. In this paper, the field investigation of vertical borehole ground heat exchangers in capital city Vilnius (Visoriai), Lithuania is presented. The numerical heat transfer model considering seven different geological strata was developed using the cylindrical heat sink model for vertical borehole inside by solving the soil mass and heat transfer equations with groundwater flow. The numerical multilayered ground vertical borehole heat transfer model was calculated and validated by in-situ thermal response test data. The numerical model results were also compared with the homogeneous finite difference model expressed by the temperature response functions (well known as “g-functions”). The practical realization of g-functions was designed in the Earth Energy Designer as a practical tool for geoengineers designing the vertical borehole plants. The temperature profiles at borehole wall at different heating times were presented and explored together with relative errors. The numerical model will be used as a practical tool for the Lithuanian Geological Survey under the Ministry of Environment to estimate the underground conditions for the consumption of shallow geothermal energy.

Experimental Measurement of Glass to Mold Heat Transfer for Computational Modeling of Container Production

2004 ◽  
Author(s):  
Matthew R. Hyre ◽  
Brenton L. Underwood
Keyword(s):  
Heat Transfer ◽  
Heat Flow ◽  
Glass Container ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Glass Temperature ◽  
Contact Conductance ◽  
One Dimensional ◽  
Experimental Apparatus ◽  
Container Production

Recent advances in numerical simulation capabilities have made the modeling of glass container forming processes feasible. These forming models must include large free surface deformations, viscoelastic behavior, conjugate heat transfer, and complex contact phenomena between the glass and the forming molds. One of the most critical inputs to these models is the heat flux between the glass and mold. A simple one-dimensional heat transfer model was developed for use in conjunction with a complex three-dimensional forming model to determine the heat flow between the glass and forming mold. Initial comparisons to experimental results indicate the simple model captures the primary physics of heat flow during forming. This paper describes an experimental effort to determine the time varying contact conductance between molten glass and container forming molds. The experimental apparatus is capable of independently varying the glass pressure, glass temperature, mold temperature, and glass type. Initial validation of the experimentally determined contact conductance function in conjunction with the one-dimensional heat transfer model utilized within a glass forming model indicate good agreement between calculated and measured results. These forming models are now able to determine final glass container properties without having to resort to the trial-and-error process currently utilized in glass container production.

scholarly journals Numerical Simulation of One-Dimensional Fractional Nonsteady Heat Transfer Model Based on the Second Kind Chebyshev Wavelet

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Fuqiang Zhao ◽  
Jiaquan Xie ◽  
Qingxue Huang
Keyword(s):  
Heat Transfer ◽  
Fractional Order ◽  
Operational Matrix ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Nonsteady Heat ◽  
One Dimensional ◽  
Linear Algebraic Equations ◽  
Chebyshev Wavelet ◽  
Nonsteady Heat Transfer

In the current study, a numerical technique for solving one-dimensional fractional nonsteady heat transfer model is presented. We construct the second kind Chebyshev wavelet and then derive the operational matrix of fractional-order integration. The operational matrix of fractional-order integration is utilized to reduce the original problem to a system of linear algebraic equations, and then the numerical solutions obtained by our method are compared with those obtained by CAS wavelet method. Lastly, illustrated examples are included to demonstrate the validity and applicability of the technique.

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