Benchmarking ANN Setup Options for Trade-Off Functions of Heat Transferring Baffle Inserted Tubes | Chapter 3 | Engineering Research: Perspectives on Recent Advances Vol. 1

Artificial Neural Networks (ANNs) have been widely used for thermal analysis of heat exchangers during the last two decades. This present research uses artificial neural networks (ANNs) to determine Nusselt numbers and friction factors for nine different baffle plate-inserted tubes. MATLAB toolbox was used to search for better network configuration prediction by using commonly used multilayer feed-forward neural networks (MLFNN) with backpropagation (BP) learning algorithm with five different training functions with adaptation learning function of mean square error and TANSIG transfer function. In this research, eighteen data samples were used in a series of runs for each of nine samples of baffle-inserted tube. The uncertainties of experimental quantities were computed by using the method presented. The uncertainty calculation method used involves calculating derivatives of the desired variable with respect to individual experimental quantities and applying known uncertainties. Up to 70% of the whole experimental data was used to train the models, 15% was used to test the outputs and the remaining data points which were not used for training were used to evaluate the validity of the ANNs. The results show that the TRAINBR training function was the best model for predicting the target experimental outputs.  The study concluded that artificial neural network methodology has been successfully applied to transient forced convective heat transfer to determine the time-averaged values of Nusselt number, friction factor, entropy generation number and irreversibility distribution ratio. It is obvious that all of the training functions are in good agreement with the experimental data set but the TRAINLM training function is the best training function for the prediction of output layer parameters.

 

Author (s) Details

Ahmet Tandiroglu
Department of Mechanical Engineering Technology, Vocational High School of Erzincan, Erzincan University, Turkey.

 

Please see the book here:- https://doi.org/10.9734/bpi/erpra/v1/2702

Numerical Study of a Buried Hemispherical Double-Tube Soil Heat Exchanger Utilizing Geothermal Energy | Chapter 8 | Current Perspective to Physical Science Research Vol. 8

 This paper presents a numerical study of a buried hemispherical double-tube soil heat exchanger utilizing geothermal energy. Since the local air wall exchange coefficient throughout the heat exchanger is unknown, a mathematical study based on the unsteady Green's function theory was developed. The complexity of the geometry prompted us to conduct a numerical study that allowed us to obtain results reflecting the importance of heat exchange. There are many applications, especially storing energy underground to optimize greenhouses according to seasonal cycles. Numerical calculations were performed using CFD code to determine the temperature distribution and verify the reliability, accuracy and physical authenticity of this work.

Author(s) Details:

Dhahri Imen,
Applied Mechanics and Engineering Laboratory, National Engineering School of Tunis, University of Tunis-El Manar, Tunis, Tunisia.

Please see the link here: https://stm.bookpi.org/CPPSR-V8/article/view/13977

Study about Optimization in Helical Grooved Tubes for Heat Transfer Enhancement Using Interdisciplinary Techniques | Chapter 7 | Research and Developments in Engineering Research Vol. 6

 In this branch, the thermal augmentation factor is examined numerically established D-optimal design and therefore the entropy study is done on the optimized arithmetic. Optimization is now a repeatedly used tool in manufacturing design. Under a certain set of variables and restraints, optimization is normally done by defining a function of an profit variable and with determining allure maximum or minimum or say, the optimized point. Efforts are in preparation to enhance the central tube, covering, or plate design in heat exchangers as well, where much study is being accomplished to maximise efficiency. The surface bettering has been energetically investigated in this regard in current decades. This sort of improving is usually dominant on television set side. In this paper, with the growth in view, the design is established interdisciplinary fields. That is, first a numerical study is acted on the helically grooved tubes to analyze the thermal augmentation factor. By comparing the deterioration-generation rates of the smooth and cut tubes, this analysis was transported. The optimum Reynolds number for that tube is the individual at which hostile entropy-production-rate is reached. Numerical results are initially legitimized with written experimental results. The chosen optimised hose is next subjected to an deterioration minimization study including the Reynolds number based on the D-optimum design for the thermal augmentation factor. The tube that has ultimate grooves, the most depth, and the minimal pitch exhibits the best depiction.  However, the optimum Reynolds number is at the point place the tube has the least deterioration generated as distinguished to the smooth tube.

Author(s) Details:

Shamoon Jamshed,
Pakistan Navy Engineering College, Karachi, Pakistan.

Please see the link here: https://stm.bookpi.org/RADER-V6/article/view/11555

Thermal Analyses of Heated Horizontal Cylinder Mounted in Vertical Circular Duct| Chapter 8 | Techniques and Innovation in Engineering Research Vol. 6

 An exploratory study is performed to scrutinize the heat transfer traits of the unsteady normal convection over a level barrel heated in air. During the boiler power-on temporary operations, the effect of heat transfer on the perimeter of the barrel is observed. Surface heat transfer distributions about the circumference of the cylinders are bestowed for Rayleigh numbers of 4.13×104 to 4.35×104 and a range of various angular position of the thermocouple (0∘, 90∘, 180∘) are examined. It is documented that the fallout heat transfer donates 1/3 of the total heat transfer convection heat transfer. The reliance of the average Nusselt number on Rayleigh number is compared opportunely with those got from the research. The findings further indicate that the position of the thermocouples has a important affect the transient heat transfer about the cylinder. The temporary heat transfer got at 90∘ and 180∘ is greater than the heat transfer got at the stagnation point (0∘). Finally, equatings are reported to envision the surface heat transfer presence of the horizontal barrel.

Author(s) Details:

Himangshu Bhowmik,
Department of Mechanical Engineering, Dhaka University of Engineering and Technology DUET, Gazipur-1707, Bangladesh.

Please see the link here: https://stm.bookpi.org/TAIER-V6/article/view/8954

Thermal Diffusion and Chemical Reaction Effects on a Hydro-magnetic Natural Convection Couette Flow between Two Vertical Porous Plates| Chapter 4 | Novel Research Aspects in Mathematical and Computer Science Vol. 4

 The goal of this work is to undertake an analytical analysis of a two-dimensional steady hydro-magnetic natural convective couette flow with mass transfer of a viscous incompressible and electrically conducting Newtonian fluid between two infinite vertical parallel plates. Taking into consideration the induced magnetic field, a magnetic field of homogeneous intensity is considered to be applied transversely to the flow direction. Suction and injection are applied to the plates on a continuous basis.

The nonlinear coupled differential equations are solved analytically using the regular perturbation approach with the Eckert number Ec (1 as the perturbation parameter. The coefficients of skin frictions at the walls, the rate of heat transfer (in terms of Nusselt numbers) from the walls to the fluid, and the rate of mass transfer (in terms of Sherwood numbers) at the walls are obtained in non-dimensional form, and the effects of different physical parameters involved in the problem on these fields are graphically discussed, and the results are physically interpreted.

Findings: Chemical reaction and thermal diffusion cause concentration to drop, but high molar diffusivity and low viscosity cause it to increase. The temperature of the fluid also drops owing to thermal diffusion, but rises due to chemical reactions.

Applications: The problem formulation and subsequent conclusions have applications in chemical engineering and production.

Author(s) Details:

Deepjyoti Kalita,
Department of Mathematics, Rabindranath Tagore University, (Erstwhile Hojai College), Assam, PIN – 782435, India.

Please see the link here: https://stm.bookpi.org/NRAMCS-V4/article/view/7032