Study of Heat Transfer and Freezing Time-Temperature Behavior of Individual Pea Grains by Numerical and Experimental Methods

2020 ◽  
Vol 13 (2) ◽  
Author(s):  
Manoj Kumar Sharma ◽  
Anil Kumar Pratihar
Keyword(s):  
Heat Transfer ◽  
Numerical Model ◽  
Transient Heat Conduction ◽  
Experimental Results ◽  
Heat Transfer Analysis ◽  
Temperature History ◽  
Transient Temperature ◽  
Freezing Time ◽  
Air Stream ◽  
Cooling Air

Abstract The present research demonstrates an accurate and simple numerical model for heat transfer analysis within spherical peas when exposed to the cold air stream in a rectangular duct. The transient heat conduction equation (THCE) is solved for spherical shaped pea grains. A detailed numerical and experimental study of freezing time-temperature history for peas has been carried out. Thermal conductivity and volumetric heat capacity are measured experimentally. Temperature-dependent thermophysical properties are used in the transient temperature prediction of peas throughout the phase change process. Crank–Nicolson method has been used for the formulation of the numerical model. The effect of important parameters, viz., the initial temperature of peas, cooling air temperature, and cooling air velocity over pea samples has been studied both numerically as well as experimentally and it has been found that there is good agreement between numerical and experimental results. The correlation coefficient of linear regression, R2, between numerically predicted and experimental results, is found to be 0.987.

scholarly journals Fast Analytic Simulation for Multi-Laser Heating of Sheet Metal in GPU

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2078 ◽  
Author(s):  
Daniel Mejia-Parra ◽  
Diego Montoya-Zapata ◽  
Ander Arbelaiz ◽  
Aitor Moreno ◽  
Jorge Posada ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Heat Transfer Analysis ◽  
Laser Beams ◽  
Temperature History ◽  
Laser Machining ◽  
Transient Temperature ◽  
Interactive Simulation ◽  
Machining Parameters ◽  
Time Space ◽  
Time Frames

Interactive multi-beam laser machining simulation is crucial in the context of tool path planning and optimization of laser machining parameters. Current simulation approaches for heat transfer analysis (1) rely on numerical Finite Element methods (or any of its variants), non-suitable for interactive applications; and (2) require the multiple laser beams to be completely synchronized in trajectories, parameters and time frames. To overcome this limitation, this manuscript presents an algorithm for interactive simulation of the transient temperature field on the sheet metal. Contrary to standard numerical methods, our algorithm is based on an analytic solution in the frequency domain, allowing arbitrary time/space discretizations without loss of precision and non-monotonic retrieval of the temperature history. In addition, the method allows complete asynchronous laser beams with independent trajectories, parameters and time frames. Our implementation in a GPU device allows simulations at interactive rates even for a large amount of simultaneous laser beams. The presented method is already integrated into an interactive simulation environment for sheet cutting. Ongoing work addresses thermal stress coupling and laser ablation.

Heat Transfer Analysis in a Modern DLN Combustor

2000 ◽  
Author(s):  
Giovanni Ferrara ◽  
Luca Innocenti ◽  
Giacomo Migliorini ◽  
Bruno Facchini ◽  
Anthony J. Dean
Keyword(s):  
Heat Transfer ◽  
Combustion Chamber ◽  
Film Cooling ◽  
Thermal Flux ◽  
Calculation Model ◽  
Heat Transfer Analysis ◽  
Turbine Blade Cooling ◽  
Air Flows ◽  
Critical Components ◽  
Cooling Air

The increasingly stringent emissions standards in recent years have mandated low gas turbine emissions and thus changed the approach to combustion chamber design. In particular, lean burners based on highly premixed fuel-air flows have become more important. These combustors, termed Dry Low NOx (DLN), can now achieve emissions of 25 ppm and below in commercial operation. This development together with the inlet turbine temperature increase has resulted in less cooling air for combustion chambers and turbine blade cooling systems. The designer now needs to optimise cooling air flows that control the wall temperature of the components that confine the hot gases. Moreover, much of the air coming from the compressor is used to premix the fuel and only a smaller fraction is now available for cooling processes. In annular combustor configurations the air available for cooling the combustion chamber walls sometimes also has to cool the first stage nozzle. So the pressure loss along the combustor cooling passages has to be limited in order to assure a suitable supply pressure for these downstream cooling passages. We analysed the cooling air flow around the liner of an annular combustion chamber and we investigated the thermal flux and friction losses. In this paper we show the development of a calculation model that allows the critical components heat transfer analysis of a typical annular combustion chamber. The code developed is based on the generalised 1–D flow treatment. We have used experimental correlations for convection, film cooling and impingement borrowed from works found in literature. The code is provided with a graphical interface that helps the user during the calculation. This code was used in practical application to optimize the PGT5B combustion chamber cooling.

Evaluation of response characteristics of thin film gauge for conductive heat transfer mode

2020 ◽  
pp. 014233122096066
Author(s):  
Tanweer Alam ◽  
Rakesh Kumar
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Heat Flux ◽  
Short Duration ◽  
Temperature Data ◽  
Heat Transfer Analysis ◽  
Transient Temperature ◽  
Conductive Heat ◽  
Sensing Element ◽  
Element Analysis

Heat transfer analysis is the one of the most important designing aspects for many engineering systems. The design prospect in the preview of heat transfer focuses on the prediction of heat flux with the help of measured transient temperature data. Thin film gauges are one of the most predominant method for the heat flux prediction especially for short duration transient temperature measurement. Thin film gauges are usually exposed to the heated environment for the measurement purpose. However, there are some prominent research areas like ablation phenomenon met to spacecraft thermal shields during re-entry to the atmosphere, for which direct exposure of the thin film gauge to the heated environment causes the functional and working difficulties associated with the gauge. In the present study, it is aimed to investigate the suitability of thin film gauge for the conduction-based short duration measurement. An experimental set up is fabricated, which is used to supply the heat load to the hand-made thin film gauge using platinum as sensing element and quartz as a substrate. The transient temperature data is recorded during experiment is further compared with the simulated temperature histories obtained through finite element analysis. The heat flux estimation for both the analysis is made using measured transient temperature data by convolute integral of one- dimensional heat conduction equation. The estimated heat flux value for the experimental and numerical result is found to be in excellent agreement.

Application of an Object-Oriented CFD Code to Heat Transfer Analysis

2008 ◽  
Author(s):  
Luca Mangani ◽  
A. Andreini
Keyword(s):  
Heat Transfer ◽  
Turbulence Models ◽  
Lateral Spreading ◽  
Impinging Jets ◽  
Experimental Results ◽  
Heat Transfer Analysis ◽  
Specific Class ◽  
Turbine Cooling ◽  
Numerical Predictions ◽  
High Flexibility

This paper is aimed at showing the performances obtained with an open-source CFD code for heat transfer predictions after the addiction of specific modules. The development steps to make this code suitable for such simulations are described in order to point out its potentiality as a customizable CFD tool, appropriate for both academic and industrial research. The C++ library, named OpenFOAM, offers specific class and polyhedral finite volume operators thought for continuum mechanics simulations as well as built-in solvers and utilities. To make it robust, fast and reliable for RANS heat transfer predictions it was indeed necessary to implement additional submodules. The package coded by the authors within the OpenFOAM environment includes a suitable algorithm for compressible steady-state analysis. A SIMPLE like algorithm was specifically developed to extend the operability field to a wider range of Mach numbers. A set of Low-Reynolds eddy-viscosity turbulence models, chosen amongst the best performing in wall bounded flows, were developed. In addition an algebraic anisotropic correction, to increase jets lateral spreading, and an automatic wall treatment, to obtain mesh independence, were added. The results presented cover several types of flows amongst the most typical for turbomachinery and combustor gas turbine cooling devices. Impinging jets were investigated as well as film and effusion cooling flows, both in single and multi-hole configuration. Numerical predictions for wall effectiveness and wall heat transfer coefficient were tested against standard literature and in-house set-up experimental results. The numerical predictions obtained proves to be in-line with the equivalent models of commercial CFD packages obtaining a general good agreement with the experimental results. Moreover during the tests OpenFOAM code has shown a good accuracy and robustness, as well as an high flexibility in the implementation of user-defined submodules.

Inverse Heat Transfer Analysis of Micro Heater Strength and Locations for Hyperthermia Treatment of Brain Tumors

2007 ◽  
Author(s):  
Maral Biniazan ◽  
Kamran Mohseni
Keyword(s):  
Heat Transfer ◽  
Brain Tumors ◽  
Transfer Problem ◽  
The Body ◽  
Least Square ◽  
Bioheat Transfer ◽  
Heat Transfer Analysis ◽  
Whole Body ◽  
Transient Temperature ◽  
Inverse Heat Transfer

Hyperthermia, also called thermal therapy or thermotherapy, is a type of cancer treatment in which the aim is to maintain the surrounding healthy tissue at physiologically normal temperatures and expose the cancerous region to high temperatures between 43°C–45°C. Several methods of hyperthermia are currently under study, including local, regional, and whole-body hyperthermia. In local hyperthermia, Interstitial techniques are used to treat tumors deep within the body, such as brain tumors. heat is applied to the tumor, usually by probes or needles which are inserted into the tumor. The heat source is then inserted into the probe. Invasive interstitial heating technique offer a number of advantages over external heating approaches for localizing heat into small tumors at depth. e. g interstitial technique allows the tumor to be heated to higher temperatures than external techniques. This is why an innovative internal hyperthermia research is being conducted in the design of an implantable microheater [1]. To proceed with this research we need complete and accurate data of the strength, number and location of the micro heaters, which is the objective of this paper. The location, strength, and number of implantable micro heaters for a given tumor size is calculated by solving an Inverse Heat Transfer Problem (IHTP). First we model the direct problem by calculating the transient temperature field via Pennies bioheat transfer equation. A nonlinear least-square method, modified by addition of a regularization term, Levenberg Marquardt method is used to determine the inverse problem [2].

Numerical Heat Transfer Analysis of Flake Ice Storage System with Nanofluids

2012 ◽  
Vol 433-440 ◽  
pp. 2716-2720
Author(s):  
Jing De Zhao ◽  
Ni Liu ◽  
Yi Wang
Keyword(s):  
Heat Transfer ◽  
Numerical Model ◽  
Storage System ◽  
Heat Transfer Analysis ◽  
Ice Storage ◽  
Electrical Load ◽  
Unsteady Heat Transfer ◽  
Numerical Heat Transfer

Ice Storage air-condition can be used to shift electrical load from on-peak hours to off-peak hours, which can bring mutual benefits to power supplier and consumers. An unsteady heat transfer numerical model is developed to predict the increment of thickness of ice layer of flake ice storage system with Cu-H2O nanofluids solidification. In this study, the speed of increment of ice layer of water and Cu-H2O nanofluids are compared.

Heat Transfer Controlled Collapse of a Cylindrical Vapor Bubble in a Vertical Isothermal Tube

1977 ◽  
Vol 99 (3) ◽  
pp. 392-397 ◽  
Author(s):  
D. R. Pitts ◽  
H. C. Hewitt ◽  
B. R. McCullough
Keyword(s):  
Heat Transfer ◽  
Vapor Bubble ◽  
High Speed ◽  
Experimental Results ◽  
Heat Transfer Analysis ◽  
Experimental Program ◽  
Bubble Collapse ◽  
Electric Heater ◽  
Vapor Bubbles ◽  
Experimental Apparatus

An experimental program was conducted to determine the collapse rate of slug-type vapor bubbles rising due to buoyancy through subcooled parent liquid in a vertical isothermal tube. The experimental apparatus included a vertical glass tube with an outer glass container providing a constant temperature water bath for the inner tube. The inner tube contained distilled, deaerated water, and water vapor bubbles were generated at the bottom of this tube with a pulsed electric heater. The parent liquid was uniformly subcooled with respect to the vapor bubble resulting in heat transfer controlled bubble collapse. Collapse rates and rise velocities were recorded by high-speed motion picture photography. Over a limited range of subcooling, the bubble collapse was well behaved, and a simple, quasi-steady boundary layer heat transfer analysis adapted from slug flow over a flat plate correlated the experimental results with a high degree of accuracy. Experimental results were obtained with tubes having inside diameters of 0.0127, 0.0218, and 0.0381 m and for a range of subcooling from 0.5 to 9.0 K.

Heat Transfer Analysis of the Micron-Scale Agglomerates of TiO2 Precursor during the Detonation Process

2011 ◽  
Vol 306-307 ◽  
pp. 1138-1141
Author(s):  
Yan Dong Qu ◽  
Xiao Jie Li ◽  
Hong Hao Yan
Keyword(s):  
Heat Transfer ◽  
Mathematic Model ◽  
Heat Transfer Analysis ◽  
Temperature History ◽  
Detonation Products ◽  
Synthesis Mechanism ◽  
Temperature Distributions ◽  
Calculation Results ◽  
Detonation Method ◽  
Detonation Process

Removing water excessively could result in the formation of sphere-like agglomerates of TiO2 precursor with 1-2 μm in size, which was used to prepare TiO2 nanoparticles by detonation method. Different temperature distributions of TiO2 precursor agglomerates influenced the components of detonation products. In order to obtain the temperature distributions, a mathematic model was introduced to study the heat transfer behaviors of the TiO2 precursor agglomerates during the detonation process. The temperature history at spherical center with different spherical radiuses and time was also studied. The calculation results were in good agreement with the experimental results. The heat transfer analysis laid the foundation for the synthesis mechanism research of TiO2 nanoparticles, and it was also helpful to design and optimize experimental procedure.

scholarly journals Analytic transient solutions of a cylindrical heat equation

Filomat ◽  
2021 ◽  
Vol 35 (8) ◽  
pp. 2617-2628
Author(s):  
K.Y. Kung ◽  
Man-Feng Gong ◽  
H.M. Srivastava ◽  
Shy-Der Lin
Keyword(s):  
Heat Transfer ◽  
Differential Equation ◽  
Partial Differential Equation ◽  
Heat Conduction ◽  
Heat Equation ◽  
Heat Conduction Equation ◽  
Separation Of Variables ◽  
Transient Heat Conduction ◽  
Transient Temperature ◽  
Transient Solutions

The principles of superposition and separation of variables are used here in order to investigate the analytical solutions of a certain transient heat conduction equation. The structure of the transient temperature appropriations and the heat-transfer distributions are summed up for a straight mix of the results by means of the Fourier-Bessel arrangement of the exponential type for the investigated partial differential equation.

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