Analysis and Modelling of Temperature at Lake’s Water – Atmosphere Interface

2021 ◽  
Author(s):  
Vassilis Z. Antonopoulos ◽  
Soultana K. Gianniou
Keyword(s):  
Heat Transfer ◽  
Energy Balance ◽  
Surface Temperature ◽  
Water Surface ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Net Radiation ◽  
Water Surface Temperature ◽  
Simulation Results ◽  
Input Variables

Abstract The knowledge of micrometeorological conditions on water surface of impoundments is crucial for the better modeling of the temperature and water quality parameters distribution in the water body and against the climatic changes. Water temperature distribution is an important factor that affects most physical, chemical and biological processes and reactions occurring in lakes. In this work, different processes of water surface temperature of lake’s estimation based on the energy balance method are considered. The daily meteorological data and the simulation results of energy balance components from an integrated heat transfer model for two complete years as well as the lake’s characteristics for Vegoritis lake in northern Greece were used is this analysis.The simulation results of energy balance components from a heat transfer model are considered as the reference and more accurate procedure to estimate water surface temperature. These results are used to compare the other processes. The examined processes include a) models of heat storage changes in relationship to net radiation (Qt(Rn) values, b) net radiation estimation with different approaches, as the process of Slob’s equation with adjusted coefficients to lake data, and c) ANNs models with different architecture and input variables. The results show that the model of heat balance describes the water surface temperature with high accuracy (r2=0.916, RMSE=2.422oC). The ANN(5,6,1) model in which Tsw(i-1) is incorporated in the input variables was considered the better of all other ANN structures (r2=0.995, RMSE=0.490oC). The use of different approaches for simulating net radiation (Rn) and Qt(Rn) in the equation of water surface temperature gives results with lower accuracy.

A hybrid PV/T solar evaporator using CO2: Numerical heat transfer model and simulation results

Solar Energy ◽  
2018 ◽  
Vol 170 ◽  
pp. 1118-1129 ◽  
Author(s):  
Pierre-Luc Paradis ◽  
Daniel R. Rousse ◽  
Louis Lamarche ◽  
Hakim Nesreddine
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Numerical Heat Transfer ◽  
Model And Simulation ◽  
Simulation Results

Optimal Design of Breakout Prediction System of Slab Continuous Casting

2012 ◽  
Vol 457-458 ◽  
pp. 138-141
Author(s):  
Yi Wang ◽  
Xin Jian Ma
Keyword(s):  
Heat Transfer ◽  
Optimal Design ◽  
Continuous Casting ◽  
Surface Temperature ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Prediction System ◽  
Slab Continuous Casting ◽  
New Development ◽  
Prediction Technique

This paper describes the new development of the breakout prediction technique based a heat transfer model. The model aims to minimize the variation in surface temperature. The breakout prediction system of slab continuous casting has been analyzed with consideration of the principles, model and thermocouples installation. The system has been designed and implemented in the steel plants.

scholarly journals Simulation and Evaluation of Heat Transfer Inside a Diseased Citrus Tree during Heat Treatment

2021 ◽  
Vol 3 (1) ◽  
pp. 19-28
Author(s):  
Shirin Ghatrehsamani ◽  
Yiannis Ampatzidis ◽  
John K. Schueller ◽  
Reza Ehsani
Keyword(s):  
Heat Transfer ◽  
Heat Treatment ◽  
Experimental Studies ◽  
Canopy Cover ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Heat Penetration ◽  
Simulation Results ◽  
Simulation And Evaluation ◽  
Temperature Time

Heat treatment has been applied in previous studies to treat diseased plants and trees affected by heat-sensitive pathogens. Huanglongbing (HLB) is a heat-sensitive pathogen and the optimal temperature–time for treating HLB-affected citrus trees was estimated to be 54 °C for 60 to 120 s from indoor experimental studies. However, utilizing this method in orchards is difficult due to technical difficulties to effectively apply heat. Recently, a mobile thermotherapy system (MTS) was developed to in-field treat HLB-affected trees. This mobile device includes a canopy cover that covers the diseased tree and a system to supply steam under the cover to treat the tree. It was proven that the temperature inside the canopy cover can reach the desired one (i.e., 54 °C) to kill bacteria. However, for HLB, the heat should penetrate the tree’s phloem where the bacteria live. Therefore, measuring the heat penetration inside the tree is very critical to evaluate the performance of the MTS. In this study, a heat transfer model was developed to simulate the heat penetration inside the tree and predict the temperature in the phloem of the diseased tree during the in-field heat treatment. The simulation results were compared with in-field experimental measurements. The heat transfer model was developed by a comparative analysis of the experimental data using the ANSYS software. Results showed that the temperature in the phloem was 10–40% lower than the temperature near the surface of the bark. Simulation results were consistent with experimental results, with an average relative error of less than 5%.

scholarly journals Numerical Study of the Thermal Model on High Uniformity Temperature Test Platform

2019 ◽  
Vol 256 ◽  
pp. 03003
Author(s):  
Zijuan Wang ◽  
Ying Zhou ◽  
Han Xiao ◽  
Shao Jingyi
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Numerical Study ◽  
Radiation Heat Transfer ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Conductive Heat ◽  
Temperature Uniformity ◽  
Test Platform ◽  
Background Temperature

The surface temperature uniformity of a test platform with an effective test area of 600 mm × 600 mm was numerically studied. The conductive heat transfer model for the test platform and the device under test (DUT) installed on the surface was established in the present work, as well as the radiation heat transfer model from the platform surface to the background temperature. The platform surface was divided into 5 or 9 regions where heated independently to make the surface temperature consistent. The temperature uniformity of these two partition designs was compared. The result shows that the 9 regions design has higher temperature uniformity at both target temperatures of -10°C and +45°C.

scholarly journals Heat Transfer Model and Quantitative Analysis of Deep Tissue Injury

2012 ◽  
Author(s):  
Arjun Chanmugam ◽  
Akanksha Bhargava ◽  
Cila Herman
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Tissue Injury ◽  
Skin Surface ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Deep Tissue ◽  
Deep Tissue Injury ◽  
Tissue Inflammation ◽  
Tissue Ischemia

Deep tissue injuries (DTI) are serious lesions which may develop in deep tissue layers as a result of sustained tissue loading or ischemic injury. These lesions may not become visible on the skin surface until the injury reaches an advanced stage making their early detection a challenging task. Early diagnosis leading to early treatment mitigates the progression of lesion and remains one of the priorities in management. The aim of this study is to examine skin surface temperature distributions of damaged tissue and develop criteria for the detection of incipient DTIs. A multilayer quantitative heat transfer model of the skin tissue was developed using a finite element based software COMSOL Multiphysics. Thermal response of the skin surface was computed during deep tissue inflammation and deep tissue ischemia and then compared with that of healthy tissue. In the presence of a DTI, an increase of about 0.5°C in skin surface temperatures was noticed during initial phase of deep tissue inflammation, which was followed by a surface temperature decrease of about 0.2°C corresponding to persistent deep tissue ischemia. These temperature differences are large enough to be detected by thermographic imaging. This study, therefore, also enhances the understanding of the previously detected thermographic quantitative changes associated with DTIs.

Pulsed Thermal Imaging Measurement of Thermal Properties for Thermal Barrier Coatings Based on a Multilayer Heat Transfer Model

2014 ◽  
Vol 136 (8) ◽  
Author(s):  
J. G. Sun
Keyword(s):  
Heat Transfer ◽  
Thermal Properties ◽  
Surface Temperature ◽  
Thermal Barrier Coatings ◽  
Thermal Imaging ◽  
Temperature Response ◽  
Heat Transfer Model ◽  
Thermal Barrier ◽  
Transfer Model ◽  
Barrier Coatings

Thermal properties of thermal barrier coatings (TBCs) are important parameters for the safe and efficient operation of advanced turbine engines. This paper presents a new method, the pulsed thermal imaging–multilayer analysis (PTI–MLA) method, which can measure the coating thermal conductivity and heat capacity distributions over an entire engine component surface. This method utilizes a multilayer heat transfer model to analyze the surface temperature response acquired from a one-sided pulsed thermal imaging experiment. It was identified that several experimental system parameters and TBC material parameters may affect the coating surface temperature response. All of these parameters were evaluated and incorporated as necessary into the formulations. The PTI–MLA method was demonstrated by analyzing three TBC samples, and the experimental results were compared with those obtained from other methods.

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