On the Corrosion Properties for Roll-Bonded One-Layer AA4045/AA3003 Modified Brazing Sheets for Automotive Heat Exchanger Application | Chapter 3 | Chemical and Materials Sciences: Developments and Innovations Vol. 6

 

The automobile industry continues to put pressure on the heat exchanger manufacturing sector to develop heat exchangers that are of less than average dimension, light, efficient, and as affordable as possible. During the service life, automotive heat exchangers are subjected to a variety of environments, including heating and cooling cycles, saltwater environment on the road surface, and mechanical loading. As a result, corrosion performance is critical, as perforation of the material could result in system failure. The corrosion behaviour of roll-bonded aluminium brazing sheets is significant since this is the most common mode of failure for automotive heat exchangers, especially with the trend toward lighter automotive parts. Furthermore, thermal treatments such as solution heat treatment, homogenization, and brazing alter the microstructure and, as a result, vary the corrosion behaviour. The qualities of the finished product, such as mechanical properties and corrosion resistance, are impacted by microstructural variation in AA3xxx that results in the development of manganese (Mn) bearing dispersoids during preheat treatment before rolling. The effect of homogenization temperature and duration on the microstructure of AA3xxx aluminium alloys has been studied, but more research is needed. The goal of this investigation was to see how different holding times during pre-heat treatments affect the corrosion behaviour of the AA4045/3003 modified brazing sheet used for automotive heat exchangers. The experimental plate samples were made from modified alloy 3003 and standard alloy 4045 in the cast and homogenised state. Accelerated laboratory corrosion tests are essential for ranking trial materials and ultimately qualifying an alloy for production. The corrosion behaviour of one-layer modified AA4045/3003 brazing sheets was examined in this chapter before brazing. The samples homogenized for 20 hours exhibited more corrosion resistance with a corrosion rate of less than 0.1 mm/y than those homogenized for longer times. The corrosion resistance deteriorated with an increase in the homogenization time. The corrosion propagation was attributed to potential differences between the brazing sheet, creating a galvanically driven perforation of the core material by the diffusion zone after accelerated salt spray testing (ASST) and electrochemical testing.

 

Author (s) Details

JS Moema
Advanced Materials Division, MINTEK, Randburg, South Africa and Department of Material Science and Metallurgical Engineering, The University of Pretoria, Private Bag X20, Hatfield Campus, Pretoria 0028, South Africa.

 

T Ramathe
Department of Material Science and Metallurgical Engineering, The University of Pretoria, Private Bag X20, Hatfield Campus, Pretoria 0028, South Africa.

 

CW Siyasiya
Department of Material Science and Metallurgical Engineering, The University of Pretoria, Private Bag X20, Hatfield Campus, Pretoria 0028, South Africa.

 

NDE Hadebe
Advanced Materials Division, MINTEK, Randburg, South Africa.

 

T Buthelezi
Hulamin Operations Proprietary Limited, Moses Mabhida Road, Pietermaritzburg, 3201, South Africa.

 

Please see the book here:- https://doi.org/10.9734/bpi/cmsdi/v6/2009

 

Individually Finned Heat Pipe Heat Exchanger for Air Conditioning with Freon R404A as Working Fluid by Localized Theoretical Analysis Using Thermal Efficiency Concept | Chapter 10 | Current Perspective to Physical Science Research Vol. 6

 This work contributes to the improvement of energy-saving in air conditioning system. The objective is to apply the thermal efficiency of heat exchangers for localized determination of the thermal performance of heat exchangers with individually finned heat pipes. The fundamental parameters used for performance analysis were the number of fins per heat pipe, the number of heat pipes, the inlet temperatures, and the flow rates of hot and cold fluids. The heat exchanger under analysis uses Freon 404A as a working fluid in an air conditioning system for cooling in the Evaporator and energy recovery in the Condenser. The theoretical model is localized and applied individually to the Evaporator, Condenser, and heat exchanger regions. The results obtained through the simulation are compared with experimental results that use a global approach for the heat exchanger. The thermal quantities obtained through the theoretical model in the mentioned regions are air velocity, Nusselt number, thermal effectiveness, heat transfer rate, and outlet temperature. The comparisons made with global experimental results are in excellent agreement, demonstrating that the localized theoretical approach developed is consistent and can be used as a comprehensive analysis tool for heat exchangers using heat pipes. The maximum absolute error for effectiveness is equal to 58.9%, and the minimum absolute error is equal to 2.2%. The maximum absolute error for heat transfer rate is equal to 41.4%, and the minimum absolute error is equal to 0.9%.

Author(s) Details:

Élcio Nogueira,
Department of Mechanic and Energy, State University of Rio de Janeiro, Brazil.

Please see the link here: https://stm.bookpi.org/CPPSR-V6/article/view/13397

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

Study on SIR Epidemic Model with Constant Vaccination: A Differential Transformation Approach | Chapter 10 | Current Approaches in Science and Technology Research Vol. 12

Vaccination initiatives have resulted in significant levels of permanent protection against the childhood disease in the general population over the years. Infectious disorders affecting children are the most common. In this paper, a SIR model is created to track the temporal dynamics of a childhood disease in the presence of a preventative vaccine. For disease control and eradication, the qualitative analysis provides the vaccine reproductive number R V. The goal of this study is to use the differential transformation method (DTM) to compute an approximation to the solution of the problem's nonlinear system of differential equations. To demonstrate the answers, graphical results are provided and quantitatively discussed.

Author (S) Details

S. F. M. Ibrahim
Department of Mathematics, Faculty of science For Girls, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia and Department of Mathematics, Faculty of Education, Ain Shams University, Heliopolis, Roxy, Cairo, Egypt.

Soad Moftah Ismail
Department of Basic science, Faculty of Engineering, Misr University For Science &Technology, Al-Motamayez District, 6Th of October City, Egypt.

View Book :- https://stm.bookpi.org/CASTR-V12/article/view/2602

Study on Adhesion of Bacterio-contaminants to Fragments of Rocks Immersed in Water: Impact of Some Chemical Properties of the Medium and Intrinsic to the Cells | Chapter 9 | Current Approaches in Science and Technology Research Vol. 12

 A study was conducted in an aquatic microcosm with the goal of determining the impact of environmental chemical factors and cell-specific characteristics on the retention of bacterial pollutants in the aquatic environment on solid substrates. Sandstone, basalt, granite, and micaschist were employed as rocky substrates. There are four main petrographic and mineralogical features in these rocks. Pseudomonas aeruginosa, Vibrio cholerae, and Enterococcus faecalis were among the bacteria obtained using normal procedures and utilised for adhesion testing. These bacteria are rod-shaped, comma-shaped, and spherical-shaped, with or without a flagellum. Furthermore, this ciliature, if present, might be single or in tufts, polar or non-polar, and can cover the entire cell. The pH of the medium, as well as the concentrations of BOM and salts, were all different. The bacteria were incubated for 180 to 1440 minutes to allow them to attach to the substrates. The adhering cells were then separated in a sterile environment by placing the pebbles in three test tubes, each containing 10 ml of sterile physiological water (0.85 percent NaCl). Bacteria found in surface or groundwater appear to be able to cling to the surfaces of inorganic rocks in various quantities. The natural cleaning of wastewater is aided by the adherence and retention of microorganisms. The adhesion of P. aeruginosa, V. cholerae, and E. faecalis changes with time. Overall, adhesion rates range from 11 to 12.44x103 cells/cm2/h, with E. faecalis adhering more quickly simply due to gravity. Environmental circumstances, as well as the chemical characteristics of rocks and soil, play a role in these rate fluctuations. Flagellum serves a dual purpose in attracting and relaunching microorganisms from their substrates.

Author (S) Details

Olive Vivien Noah Ewoti
Laboratory of Hydobiology and Environment, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde 1, PO Box 812, Cameroon.

Daniel Ebang Menye
University of Maroua, Higher Teacher’s Training School College, P.O Box 55 Maroua, Cameroon.

Raoul Polycarpe Tuekam Kayo
Laboratory of microbiology, Department of Microbiology, Faculty of Science, University of Bamenda, Cameroon.

Luciane Marlyse Moungang
Laboratory of Hydobiology and Environment, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde 1, PO Box 812, Cameroon.

Antoine Tamsa Arfao
Laboratory of Hydobiology and Environment, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde 1, PO Box 812, Cameroon.

Samuel Davy Baleng
Laboratory of Hydobiology and Environment, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde 1, PO Box 812, Cameroon.

Yves Yogne Poutoum
Laboratory of Hydobiology and Environment, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde 1, PO Box 812, Cameroon.

Moïse Nola
Laboratory of Hydobiology and Environment, Department of Animal Biology and Physiology, Faculty of Science, University of Yaounde 1, PO Box 812, Cameroon.

View Book :- https://stm.bookpi.org/CASTR-V12/article/view/2601

Thermal and Flow Analysis of the Helical Coil Heat Exchanger Used in an Aqueous Solution of Ammonium Nitrate Solubility (ANSOL) with 20% H2O and 80% AN | Chapter 8 | Current Approaches in Science and Technology Research Vol. 12

 The goal of the case study is to determine the steam flow rate and saturation temperature that will allow a solution of water and ammonia nitrate (ANSOL) to be heated in a shell and helical coil tube heat exchanger during a time period without the ANSOL solution crystallising. The solution's desired production per batch is 5750 kg in 80 minutes. The heat transfer rate and temperature profiles that satisfy the imposed criterion within a given degree of safety and at the lowest possible cost in steam generation are determined using the concepts of efficiency and effectiveness. The Reynolds number, Nusselt number, and global heat transfer coefficient for the shell and helical coil tube heat exchanger are intermediate quantities required to achieve the goal. The water is heated for a predetermined amount of time before the ammonium nitrate is introduced to a given flow at a predetermined mass flow rate.

Author (S) Details

Élcio Nogueira
Department of Mechanics and Energy - DEM, State University of Rio de Janeiro - UERJ, Resende, Brazil.

View Book :- https://stm.bookpi.org/CASTR-V12/article/view/2600