Journal of Engineering and Thermal Sciences: Table of Contents

Thermal shock problem of a generalized thermoelastic solid sphere affected by mechanical damage and thermal diffusion

Youssef, Hamdy M. — 2021-06-30T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 1, Issue 1, 2021, p. 1-16.
Hamdy M. Youssef
A mathematical model was created in this article, which consists of a thermoelastic, unified, and isotropic rigid sphere subjected to thermal diffusion. Thermal and chemical potential shocks of a diffusive substance have loaded the sphere's bounding structure. The governing equations were established in the form of a theory of generalized thermoelastic diffusion with mechanical damage taken into account. The temperature increment, concentration, pressure, displacement, stress, and chemical potential numerical effects have been expressed in figures with different values of the mechanical damage parameter, thermal relaxation time, and diffusional relaxation time. All the studied functions are significantly affected by the mechanical damage parameter, radial distance, time, thermal, and diffusional relaxation times. In the Lord-Shulman model, heat, diffusion, and mechanical waves spread at finite speeds on the thermoelastic solid sphere.

On the concept of a conformable fractional differential equation

Shaw, Soumen — 2021-06-30T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 1, Issue 1, 2021, p. 17-29.
Soumen Shaw, Mohamed I. A. Othman
A new simple well-behaved definition of the fractional derivative termed as conformable fractional derivative and introducing a geometrical approach of fractional derivatives, non-integral order initial value problems are an attempt to solve in this article. Based on the geometrical interpretation of the fractional derivatives, the solution curve is approximated numerically. Two special phenomena are employed for concave upward and downward curves. In order to obtain the solution of fractional order differential equation (FDE) with the integer-order initial condition, some new criteria on fractional derivatives are proposed.

Hyperbolic two-temperature generalized thermoelasticity with fractional order strain of solid cylinder

A. El-Bary, Alaa — 2021-09-13T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 1, Issue 2, 2021, p. 30-42.
Alaa A. El-Bary
A novel mathematical model of thermoelastic of a homogenous isotropic solid cylindrical infinite medium has been constructed in this paper. Thermally shocked is the bounding surface of the cylinder. In the sense of the hyperbolic two-temperature generalized thermoelasticity with fractional stress theory, the governing equations have been taken. Different values of the fractional order and two-temperature parameters have shown numerical results for the dynamical and conductive temperature increment, strain, displacement, and average stress, which are graphically applicable to all the functions studied. The fractional-order parameter has significant effects on stress and displacement distributions, while it has little effect on the dynamical and conductive temperatures increment and significant effects on all studied functions as well as on the two-temperature parameter. The two-temperature hyperbolic model is precious and effective.

Heat transfer and the influence of electromagnetic field and thermal time during temperature distribution in human tissue

Lotfy, Khaled — 2021-10-12T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 1, Issue 2, 2021, p. 43-53.
Khaled Lotfy, Alla El-Bary
The Penne’s bio-heat transfer equation can be used with normal mode technique to describe the characterizing of the temperature fluctuation in muscles. The analytical solutions of heating pattern is obtained in a closed-form when the propagation of ultrasonic waves in tissue system are taken into consideration. The impact of external electromagnetic field is used to investigate the influence of temporal and spatial distributions of temperature. The numerical simulations during the 2D and 3D graphs can be obtained for human tissue in simplified geometry in the context of the derived method. The normal mode analysis is used as a mathematical technique to solve the bioheat transfer equation analytically with some conditions to get the complete solution of the main variables in this model.

Influence of laser pulse on plane waves propagating in a thermoelastic medium with micro-temperature under the DPL model

Jahangir, Adnan — 2021-11-11T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 1, Issue 2, 2021, p. 54-64.
Adnan Jahangir, Adiya Dar, Mohamed I. A. Othman
In this paper, estimation is made to investigate the influence of thermal loading due to laser pulse on elastic waves. The material through which the waves are propagating is homogeneous and isotropic in nature. Heat conduction through the media is analyzed by the model proposed by dual-phase-lag theory (DPL). The governing non-dimensional equations are solved by using the approximated harmonic solution. The expression for the field variables is obtained generally and represented graphically for a particular medium.

Significance of fin tip temperature on the heat transfer rate and thermal efficiency of a convective-radiative rectangular fin with variable thermal conductivity

Sobamowo, M. G. — 2021-12-28T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 1, Issue 2, 2021, p. 65-80.
M. G. Sobamowo, O. A. Adeleye, A. A. Yinusa, M. O. Oyekeye, M. A. Waheed
In this work, effect of fin tip temperature on the rate of heat transfer and thermal efficiency of a rectangular convective-radiative fin with temperature-dependent thermal conductivity is analyzed using differential transformation method. The results of the power series solutions are verified numerically, and very good agreements are established. Also, the symbolic solutions are used to examine the effects of the conductive-convective and nonlinear thermal conductivity parameters on the thermal performance of the passive device. It is found that when the nonlinear thermal conductivity parameter increases, the fin tip temperature increases. However, the temperature at the tip of the fin decreases as the conductive-convective parameter increases. The thermal efficiency of the fin increases as the fin tip temperature and nonlinear thermal conductivity parameters are augmented but an increase conductive-convective parameter causes the fin tip temperature and the thermal efficiency of the extended surface to reduce. An increase in the conductive-convective parameter causes decrease the temperature distribution and thermal efficiency in the passive device. However, the efficiency of the fin increases as the nonlinear thermal conductivity parameter increases. When nonlinear thermal conductivity and conductive-convective parameters increase, the rate of heat transfer at the fin base increases. The developed analytical solutions provide a good platform for the nonlinear thermal analysis of the fin and proper design of the extended surfaces in thermal systems.

Using total equivalent temperature difference approach to estimate air conditioning cooling load in buildings

Omar, Ihab — 2022-06-30T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 2, Issue 1, 2022, p. 59-68.
Ihab Omar, A. M. Mohsen, Karrar A. Hammoodi, Hasan A. Al-Asadi
The objective of this study is to provide a simplified worksheet based on the Total Equivalent Temperature Difference (TETD) Approach to estimate a building’s cooling load under Iraqi climate conditions. The heating, ventilation and air conditioning (HVAC) system was applied to scientific laboratories at the College of Engineering, University of Warith Al-Anbiyaa, Karbala, Iraq. The study estimates the cooling load of the building, which consists of 10 zones. Cooling load elements such as ventilation, lighting, walls, floors, roofs, windows, infiltration, and human factors were considered. The worksheet provides an appropriate alternative for easy and fast prediction within Iraq's climate conditions.

The vibration of a thermoelastic nanobeam due to thermo-electrical effect of graphene nano-strip under Green-Naghdi type-II model

Youssef, Hamdy M. — 2022-06-30T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 2, Issue 1, 2022, p. 1-12.
Hamdy M. Youssef, Abdullah A. Al Thobaiti
In this paper, a new analysis of thermoelastic, homogeneous, and isotropic nanobeams has been constructed in the context of the Green-Naghdi type-II heat conduction law. The first end of the nanobeam is based on a graphene strip, which contains an electrical current with a small voltage which is a novel application. Under simply supported boundary conditions with fixed side ratios, the nanobeam has been thermally loaded with a heat source due to the thermal effect of the electrical current. On the time variable, the Laplace transform technique was utilized to solve the governing differential equations. The solutions were computed in the Laplace transform’s domain. Tzou’s approximation technique based on an iteration formula was used to calculate the Laplace transform inversions numerically. The numerical findings for various values of the electrical voltage and electrical resistivity of the graphene nano-strip have been displayed using graphs illustrating distinct scenarios. All the nanobeam’s researched functionalities have been reported to be influenced by electrical voltage and electrical resistivity. The electrical voltage and resistivity of a graphene nano-strip might be utilized as a tuner to regulate the nanobeam's vibration and energy.

Dual-phase-lag model on microelongated thermoelastic rotating medium

Othman, Mohamed I. A. — 2022-06-30T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 2, Issue 1, 2022, p. 13-26.
Mohamed I. A. Othman, Sarhan Y. Atwa, E. E. M. Eraki, Mohamed F. Ismail
The dual-phase-lag (DPL) model is applied to study the influence of rotation on a two-dimensional micro-elongated thermoelastic medium problem. Mechanical force along with the layer of the elastic half-space interface and micro-elongated thermoelastic half-space is applied. The analytic expressions for displacement component, temperature distribution, micro-elongational scalar and stress components have been derived and represented graphically. The rotation has been studied in the presence DPL model and Lord-Shulman theory.

Hybrid energy efficiency mapping in major Saudi locations using small wind turbine-solar systems

Alghamdi, Abdulrahman — 2022-06-30T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 2, Issue 1, 2022, p. 46-58.
Abdulrahman Alghamdi, Talal S Mandourah
The use of fossil fuels of all kinds, such as natural gas, coal and petroleum in energy production, is the main cause of environmental pollution from air, water and soil, which is the direct cause of acid rain, the destruction of forests, the acidity of lakes, and the extinction of many living creatures that could not resist what happened Burning this fuel is due to a change in the surrounding environment. From this, it becomes clear to us the need for new sources to produce clean energy that does not pollute the environment, and work must be developed on these new sources for use in the production of clean energy in the coming years. The purpose of this work is to determine the efficiency of vertical axis turbines to be among the components of a hybrid system (solar/wind) to generate electric power in the Kingdom of Saudi Arabia. The work seeks to answer the research question, what is the efficiency of vertical axis turbines in generating electricity within a hybrid system (solar/wind) to generate electric power in the Kingdom of Saudi Arabia. The aim of the work is to analyze the vertical axis turbines and determine efficiency within the hybrid system in the regions of Saudi Arabia. There are many renewable energy sources (wind, solar thermal energy, solar photovoltaic, biomass, small and large hydropower and geothermal energy). But their efficiency is not stable from time to time, so the idea of hybrid energy came to make up for the shortage, by integrating the energy source Renewables with one or more other sources of energy (In 1999, McGowan and Manwell (1999) presented a summary of WND-PV-DSL HPS progress in the United States.) whether it is a non-renewable or renewable source [1].

An efficient solar water desalination system using natural vacuum pressure

Al-Muylaba, Mohammed — 2022-06-30T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 2, Issue 1, 2022, p. 27-45.
Mohammed Al-Muylaba, A. M. Abdel Dayem
An innovative design of a solar natural vacuum desalination (SNVD) system is proposed and investigated. To obtain a vacuum pressure in a desalination chamber its height is considered as 9.5 m. The waste heat in the system is efficiently utilized for both brine and distilled water. Seawater is preheated by the produced warm water, then, it is heated again by the outlet rejected hot brine before it is charged into the evaporation chamber. In addition, inlet pure water to a flat-plate collector is preheated by the condensation latent heat of the evaporated vapor from the evaporation chamber. Later, the outlet hot water from the collector is used as a heat source to the evaporation process. An optimum design of the system components was provided under the actual weather conditions for the shortest day of the year. It was found that the collector area is required to be 23 m2 to produce 66.6 liter of distilled water during. A mathematical modeling of the system was provided to establish a transient simulation and investigate the hourly performance of the system. Based on the annual performance of the system, the system can produce 76.5 liter of distilled water daily that is corresponding to 3.5 liter per one quadratic meter of collector. The annual average specific productivity of the system is obtained as 1.44 liter per kWh of solar radiation. Moreover, the maximum annual production is estimated as 92.88 liter of distilled water per day. Accordingly, the evaporation ratio (ER) is dependent on the solar irradiation and the annual average is found 0.0175 (or 1.75 %) where the gain output ratio (GOR) was estimated as 0.97 on yearly average basis.

Transient three-dimensional magnetohydrodynamic flow of heat and mass transfer of a Casson nanofluid past a stretching sheet with non-uniform heat source/sink, thermal radiation and chemical reaction

Odesola, A. S. — 2022-10-18T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 2, Issue 2, 2022, p. 100-113.
A. S. Odesola, I. O. Abiala, M. G. Sobamowo, O. J. Fenuga
This study considered the effect of chemical reaction on transient magnetohydrodynamic flow of heat and mass transfer of a Casson nanofluid past a stretching sheet with non-uniform Heat Source/Sink. The highly nonlinear partial differential equations governing the fluid flow alongside its boundary conditions are formulated and suitable similarity variables are introduced to transform the nonlinear partial differential equations into a set of coupled ordinary differential equations. The results revealed that as the Casson fluid parameter increases, the yield stress reduces thereby reducing the velocity, temperature, and concentration profiles. Magnetic parameter, chemical reaction parameter, stretching ratio parameter and unsteadiness parameter can be used to adjust the fluid velocity, temperature and concentration distributions. The effects of local skin friction coefficients, local Nusselt and Sherwood numbers are also shown and considered using tables. The results revealed that the unsteadiness parameter, Casson fluid parameter and magnetic parameter reduces the momentum boundary layer thickness along x and y direction. The work provides physical insight into the thermo-fluidic flow phenomena of Casson nanofluid under the impacts of magnetic field, internal heat generation and chemical reaction.

The dual-phase-lag bioheat transfer of a skin tissue subjected to thermo-electrical shock

Youssef, Hamdy M. — 2022-10-25T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 2, Issue 2, 2022, p. 114-123.
Hamdy M. Youssef, Raafat A. A. Salem
The current paper is dealing with the thermal reaction and response of skin tissue subjected to a constant heat flux due to thermo-electrical shock on the bounding plane. The dual-phase-lag bio heat conduction equation based on the Tzou model has been applied and solved in the Laplace transform domain by using a direct method. The numerical inversions of the Laplace transform, and numerical solution has been obtained. The thermos-electrical shock for a small value of time has been considered with constant voltage and resistance. The temperature increment responses have been obtained and discussed with various values of voltage, resistance, and dual-lag value times. Moreover, a comparison between the well-known three models of bioheat conduction of Pennes, Ventott-Cattaneo, and Tzou has been shown in the figure. The results show that the voltage, resistance, and dual-lag value of times have significant effects on the temperature increment distribution and the thermal wave propagation through the skin tissue.

Eigen value approach with memory dependant derivative on homogeneous isotropic infinitely extended rotating plate of a finite thickness in absence of heat source

Chakraborty, S. — 2022-11-03T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 2, Issue 2, 2022, p. 69-83.
S. Chakraborty, A. Lahiri, B. Das
Our present manuscript is an attempt to derive a model of generalized thermoelasticity with dual phase lag heat conduction by using the methodology of memory dependent derivative for a isotropic rotating plate subject to the prescribed boundary conditions with constant magnetic and electric intensities. Two integral transform such as Laplace transform for time variable and Fourier transform for space variable are employed to the governing equations to formulate vector-matrix differential equation which is then solved by eigenvalue approach methodology. The inversion of two integral transformations is carried out using suitable numerical techniques. Numerical computations for displacement, thermal strain and stress component, temperature distribution are evaluated and presented graphically under influences of different physical parameters.

Unsteady state heat transfer analysis of a convective-radiative rectangular fin using Laplace Transform-Galerkin weighted residual method

Sobamowo, Gbeminiyi M. — 2022-11-26T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 2, Issue 2, 2022, p. 84-99.
Gbeminiyi M. Sobamowo, Ahmed A. Yinusa, Zainab O. Dere, Rasheed O. Saheed, Ridwan O. Ola Gbadamosi
The present investigation is concerned with the development of non-power series solutions for the unsteady state nonlinear thermal model of a radiative-convective fin having temperature-variant thermal conductivity using Laplace transform-Galerkin weighted residual method. In the study, it is demonstrated that the symbolic solutions do not involve a large number of terms, complex mathematical analysis, high computational cost, and time as compared to the power series solutions in previous studies. The solutions allow effective predictions of the extended surface thermal performance over a large domain and time. The results of the non-power series solutions are verified numerically, and very good agreements are established. Parametric studies are carried out with the aid of the symbolic non-power solutions. It is found that as the conductive-convective and conductive-radiative increase, temperature distribution decreases since the rate of heat transfer becomes augmented and hence, the fin thermal efficiency is improved. Additionally, when the thermal conductivity of the fin increases, the temperature distribution in the passive device increases. The temperature increases with time at the different positions in the fin. Following the time histories of the solution, it is shown that unsteady state solutions converge to a steady state as time progresses. It could therefore be stated the developed non-power series analytical solutions provide a good platform for comparison of the nonlinear thermal analyses of fins in thermal systems.

Wave propagation in different theories of fractional thermoelasticity

Singh, Baljeet — 2023-05-01T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 3, Issue 1, 2023, p. 1-10.
Baljeet Singh
In the present paper, the theories of fractional thermoelasticity with derivative and integral fractional orders are employed to study the homogeneous plane waves and the Rayleigh surface waves. The governing equations of homogeneous and isotropic generalized fractional thermoelasticity are solved for plane wave solutions and a dispersive velocity equation is obtained. There exists one transverse and two coupled longitudinal waves in a two-dimensional model of fractional thermoelastic medium where the speeds of coupled longitudinal waves are found to be dependent on the derivative and integral fractional orders. The Rayleigh waves is also studied along the traction-free surface of a half-space of a generalized fractional thermoelastic solid. The governing equations are solved for the general surface wave solutions which follow the decaying conditions in the half-space. A Rayleigh wave secular equation is obtained for thermally insulated surface. For a particular example of the present model, the numerical values of the speeds of coupled longitudinal waves and the Rayleigh wave are computed and graphically illustrated to visualize the effects of derivative and integral fractional orders and the circular frequency on the wave speeds.

Influence of the fractional-order strain on an infinite material with a spherical cavity under Green-Naghdi hyperbolic two-temperature thermoelasticity theory

Youssef, Hamdy M. — 2023-06-26T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 3, Issue 1, 2023, p. 11-24.
Hamdy M. Youssef, Abdulrahman A. Alghamdi
In this work, a novel mathematical model of thermoelastic, homogenous, isotropic, and infinite medium with a spherical cavity has been constructed. Under the hyperbolic two-temperature Green-Naghdi theory of thermoelasticity type-I and type-III with fractional-order strain, the governing equations have been established. The bounding surface of the cavity has been thermally loaded by a ramp-type heat and is connected to a rigid foundation which prevents volumetric strain. Different values of the fractional-order and two-temperature parameters have shown numerical results for the dynamical and conductive temperature increment, strain, displacement, and average of principal stresses, which are graphically applicable to all the functions studied. The fractional-order parameter has significant effects on stress and strain distributions, while it has a limited effect on the dynamical and conductive temperatures increment. The hyperbolic two-temperature parameter has significant effects on all studied functions based on Green-Naghdi models of type-1 and type-II. Moreover, the ramp-time heat parameter has a significant impact on all the studied functions under all the studied models of thermoelasticity.

Plane waves in an isotropic thermoelastic diffusive material using strain gradient theory

Singh, Baljeet — 2023-12-23T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 3, Issue 2, 2023, p. 25-40.
Baljeet Singh, Himanshu Singla
The governing equations of motion for an isotropic strain-gradient thermoelastic material with diffusion are formulated in context of Lord and Shulman generalization of thermoelasticity and are further specialised for a two dimensional plane. Plane harmonic solution of the governing equations in two-dimension suggests the existence of five plane waves which include four coupled longitudinal waves and a shear vertical wave. A numerical example is considered to illustrate graphically the effect of frequency, measure constant of diffusion, measure constant of thermo-diffusion, thermal relaxation time, diffusive relaxation time and the coefficients of hyperstress tensor on the phase speed and attenuation coefficients of the plane waves.

Development and analysis of thermal flow field: a new experimental approach

Pal, Arun Kiran — 2023-12-23T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 3, Issue 2, 2023, p. 41-46.
Arun Kiran Pal
A new approach to experimental investigation of thermal flow field produced along an isothermal plate of finite dimensions in free convection is presented. The experimental procedure is based upon a flow visualization technique developed earlier by author. The contribution of this paper apparently is that a physical grid placed in the light path of a photographic flow visualization system enhances the ability to discern growth of thermal flow field produced due to temperature difference between a body and its surroundings. The results obtained from flow visualization experiment are verified with a correlation predicted by earlier published work.

Evaluation of the hardness and wear behavior of date seed powder/epoxy composites as potential biomaterials

K. Hassan, Mohamed — 2023-12-27T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 3, Issue 2, 2023, p. 47-61.
Mohamed K. Hassan, Mohammd Assas
The date palm, or Phoenix dactylifera, is a crop that is grown for food and is used by many people on a regular basis. The cultivation of date palms, their processing, and consumer demand all produce tons of waste. Date palm seeds can account for up to 10 % of the total weight of the fruits. A topic of interest for research is the application of date seed waste in the fields of engineering, nutrition, and cosmetics. This work aims to show that epoxy/palm seed date composites are suitable for use as biomaterials by examining their wear behavior. Give a brief introduction to a few ideas before going over the fundamental idea of wear resistance. Future wear resistance improvements in biomedical applications and other industries that might benefit from this addition will continue to be achieved through the use of date palm seed microparticles in epoxy. In this study, epoxy composites containing palm seed particles are made by the mixing procedure. The studied composites made from date palm seed powder particles has micron particle size of 150 which is mixed with epoxy as a matrix. The percentages of date palm seeds are varying from 5 % to 20 %. The 20 percent sample had the best results, losing 7.03 percent of their starting weight. The 10 percent group, which lost 9.4 percent, the 15 percent group, which lost 12.2 percent, and the 5 percent sample, which lost 19.95 percent, were the next in line. Each of the four samples had 1 kg to 5 kg of weight applied to them at five different rotation speeds. Upon analysis of all the samples under investigation, it was discovered that the date palm seeds enhanced and increased wear resistance, leading to better outcomes.

Optimization and experimental validation of the air intake holes of the lithium-ion battery pack

Bakar, Oya — 2024-01-24T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 4, Issue 1, 2024, p. 1-19.
Oya Bakar, Murat Uysal, Ahmet Feyzioğlu
Energy storage systems enable the storage of energy and provide access to carbon-neutral, environmentally friendly energy whenever or wherever it is needed. Lithium-ion batteries are currently the most preferred type among various battery technologies and are widely used in energy storage systems. Some of the features that make lithium-ion batteries advantageous include high energy density, long life, low maintenance requirements, and high operating voltage. The growing demand for energy throughout the day increases the need for batteries with high storage capacity. However, the increased capacity also leads to heating issues in lithium-ion batteries. The heating problem in lithium-ion batteries can result in nonhomogeneous temperature distribution, shortened lifespan, thermal runaway, increased internal resistance, and performance loss. Therefore, an effective thermal management system is essential for cooling lithium-ion batteries. This study aims to provide insight into the forced air cooling of prismatic 280 Ah LiFePo4 batteries, which have limited information in the literature and are more prone to overheating compared to lower-capacity batteries. In this study, five different battery pack case designs, each with different sizes and numbers of air intake holes, were determined and modelled using the SolidWorks program. Within the battery pack cases, 16 280 Ah lithium-ion batteries are placed, and an axial fan is used to cool these batteries. Initially, computational fluid dynamics analyses of the five different designs were performed in the SolidWorks Flow Simulation program. An experiment was then conducted on the design that provided the most efficient thermal management to validate the numerical results. The selected design, fulfilling the purpose of homogeneous temperature distribution and having the minimum temperature difference between batteries, was designated as Design 5. It exhibited a 62 % improvement in cooling performance with a 0.25 °C temperature difference, indicating successful temperature homogeneity between batteries. During a two-hour experiment with a 140 A discharge current, temperature measurements were taken from the surfaces of the batteries using thermocouples. Finally, the maximum error rate between experimental and numerical studies was determined to be 1.47 %, indicating successful validation of the numerical study. The air intake hole optimization, a novel design approach, prevents temperature distribution inhomogeneity caused by the distance of the batteries to the fan and offers an effective way to cool down high-capacity 280 Ah batteries.

Sector orifice with a correlation-based analysis

Panda, Santosh Kumar — 2024-02-17T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 4, Issue 1, 2024, p. 20-29.
Santosh Kumar Panda
In single and multiphase flows, an orifice is a vital flow-measuring and flow-controlling device that operates on Bernoulli’s theorem on the determination of the pressure drop (∆p). Laboratory, petroleum, energy, nuclear, mining, chemical, processing, and food industries all depend on flow monitoring and flow regulations. A sector or segmental orifice meter is a much simpler device used for drainage and sediment-laden type non-homogeneous flow. Sector orifice meter analysis is the rate of flow, pressure and velocity profile concerning input parameters to find out the ∆p and coefficient of discharge (Cd) of an orifice meter. The present study varies with different sector angles (θ), Reynolds number (Re) and space ratio (s/d) of the sector orifice for the flow analysis with the use of CFD (Ansys. Inc) based study. The numerical simulation range considered for θ (30°-180°), Re (10000-100000), and s/d (0.1-0.9). To compute the flow rate, ∆p and Cd by using air as a working fluid to present a flow problem through high viscous flow. The simulation also presents the pressure and velocity profiles along the flow on the variant of Re, θ and s/d. Based on the numerical data a correlation developed which will help the measurement through sector orifice for wide range of future application. With the comparison of the existing literature, this will give a good contribution to sector orifice for accurate flow measurement for high viscous flow.

Failure analysis of gas turbine in first stage turbine blades in an urban power plant

Hassan, Mohamed K. — 2024-03-12T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 4, Issue 1, 2024, p. 46-65.
Mohamed K. Hassan, Waheeb M. Sindi, Ahmed Mohamed, Ahmed H. Backar
The Combined Cycle Power Plants (CCPP) are widely known as the most efficient power plants. The concept of CCPP represented in Brayton and Rankin cycles combined to achieve the highest efficiency in power generation. During the fact finding, while performing the major outage, at 77,521 running hours some of the turbine blades at 1st stage found suffering from severe damages and sulfuric acid thick layer accumulated in the cooling airfoils. The blades were new, also known as the most essential and costly component installed after Hot Gas Path Inspection (HGPI) at 42,000 running hours. The main objective of this work is to study the surrounding parameters that directly affect the lifetime of the turbine blades. Furthermore, XRD analysis for new and used turbine blades are studied as well as the EDS analysis for the coating layers which are used to enhance the surface life of gas turbine blades. Corrective maintenance, on the other hand, has been undertaken to overcome the performance deterioration caused by wear, which is the result of any machine or plant’s operation. A gas turbine cannot be run reliably unless wear reserves are checked and, if necessary, restored during inspections and maintenance operations. These are performed to determine the machine's condition and the necessary condition-based repairs. The principal types of gas turbine inspection have been investigated and presented, including minor inspection, hot gas inspection, extended-scope hot gas path examination, and major inspection. Lifetime extension (LTE) measures are derived from these inspection types and go beyond the scope of a major inspection. Nondestructive testing is performed on the gas turbine’s key components. Furthermore, due to the high degree of contamination in the fuel, the turbine section must be cleaned at regular intervals. As a result of the examinations, replacement, and refurbishment intervals for important components, as well as outage time, could be recommended.

Fourier series method for the stability solution of simply supported thin beams on two-parameter elastic foundations of the Pasternak, Filonenko-Borodich, Hetenyi or Vlasov models

Ike, Charles Chinwuba — 2024-03-16T00:00:00Z

Journal of Engineering and Thermal Sciences, Vol. 4, Issue 1, 2024, p. 30-45.
Charles Chinwuba Ike
The analysis of stability problems of beams on two-parameter foundations (Bo2PFs) is an important part of their design for compressive loads. This work presents novel first principles derivation of the governing differential equations of elastic stability (GDES) of thin beams resting on two-parameter elastic foundations of the Pasternak, Filonenko-Borodich, Hetenyi or Vlasov models. The requirements of translational and rotational equilibrium of all the applied, reactive and internal forces on an infinitesimal segment of the Bo2PF and the laws of infinitesimal calculus were used to formulate the GDES as a fourth order ordinary differential equation (ODE) in terms of the transverse displacement function ux. The GDES is non-homogeneous in the presence of applied transverse load qx but homogeneous when qx vanishes. This study presents the Fourier series method (FSM) for solving the governing differential equation of stability (GDES) for the case of Dirichlet boundary conditions. The FSM has the advantage of amenability to differentiation, and integration due to the orthogonality properties of the sinusoidal functions. Implementation of the FSM by assuming the unknown function in the GDES as a Fourier series of infinite terms and the exploitation of orthogonalization simplifies the problem to an algebraic eigenvalue problem which is the characteristic buckling equation. The exact eigenvalues are found by algebraic solution of the buckling equation. The exact eigenvalues were used to find the exact buckling loads and the exact buckling load coefficients. The critical buckling load was found to correspond to the first buckling mode (n= 1), and is identical with previous solutions in the literature. Numerical calculations for the critical buckling load parameters Kcr were presented for the Bo2PF problem for values of the dimensionless foundation parameters k-1= 0, k-2= 0; k-1= 100, k-2= 0; k-1= 0, k-2= 1; k-1= 100, k-2= 100; k-1= 0, k-2= 2.5; k-1= 100, k-2= 2.5. The present solutions were compared with previous solutions for Kcr in the literature. The comparison shows that the present FSM results are identical with previous results obtained using various other methods such as Recursive Differentiation Method, Finite Element Method, Generalized Integral Transform Method (GITM) and Stodola-Vianello Iteration Method. The study has illustrated the effectiveness of the FSM for solving Bo2PFs.