Pub Date : 2019-09-01DOI: 10.13189/ujme.2019.070505
F. Alharbi, A. Alromaih, Sulaiman AlHudaithi, Abdullah AlHusayyani, Talal AlQadhi, Ali Sulaiman Alsagri, Abdul Rahman Alateyah, M. Basha
A complete air conditioning system has been developed to control ambient conditions such as temperature, relative humidity, air movement, etc. in an economical manner for AlFahad Mosque located Unaizah in qassim region K.S.A. In this paper, the calculations were carried out taking into account the ASHRAE standards. For space references and calculations, the plan is developed by AUTO CAD. After taking the plan investigated the location and materials used for construction, based on the study theoretical thermal load calculations were performed by the E20 Method for number of rooms as per the plan and summarizing. The present plan has one huge room of each floor. Based on the heat load calculations, cfm values were found for number rooms and summarized for entire building. Obtained the cfm for first floor as one room and ground floor as one room and add for total cfm for the AlFahad mosque. The object of the paper is about the cooling load calculation for the AlFahad Mosque at Unaizah Qassim Region Saudi Arabi (K.S.A.). The load calculation is carried out by using E20 Manually and HAP software. Nowadays, people are estimating the load calculation by approximation method i.e. by giving dimensions of building which the sellers are estimating roughly tonnage of refrigeration (market method or ALGhaith company method). These cooling load calculations obtained, which is under or over the comfort condition. To overcome this problem, the cooling load calculated by E20 manual method, HAP software and compared.
{"title":"Comparison of Cooling Load Calculations by E20 and HAP Software","authors":"F. Alharbi, A. Alromaih, Sulaiman AlHudaithi, Abdullah AlHusayyani, Talal AlQadhi, Ali Sulaiman Alsagri, Abdul Rahman Alateyah, M. Basha","doi":"10.13189/ujme.2019.070505","DOIUrl":"https://doi.org/10.13189/ujme.2019.070505","url":null,"abstract":"A complete air conditioning system has been developed to control ambient conditions such as temperature, relative humidity, air movement, etc. in an economical manner for AlFahad Mosque located Unaizah in qassim region K.S.A. In this paper, the calculations were carried out taking into account the ASHRAE standards. For space references and calculations, the plan is developed by AUTO CAD. After taking the plan investigated the location and materials used for construction, based on the study theoretical thermal load calculations were performed by the E20 Method for number of rooms as per the plan and summarizing. The present plan has one huge room of each floor. Based on the heat load calculations, cfm values were found for number rooms and summarized for entire building. Obtained the cfm for first floor as one room and ground floor as one room and add for total cfm for the AlFahad mosque. The object of the paper is about the cooling load calculation for the AlFahad Mosque at Unaizah Qassim Region Saudi Arabi (K.S.A.). The load calculation is carried out by using E20 Manually and HAP software. Nowadays, people are estimating the load calculation by approximation method i.e. by giving dimensions of building which the sellers are estimating roughly tonnage of refrigeration (market method or ALGhaith company method). These cooling load calculations obtained, which is under or over the comfort condition. To overcome this problem, the cooling load calculated by E20 manual method, HAP software and compared.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"129 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120881902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.13189/UJME.2019.070413
C. Çiflikli, Bilgin Yazlik
In a wireless communication system, cooperative diversity can be used to combat fading effects. In cooperative diversity, the system uses idle antennas, which are located at different locations, as relays. Cooperative communication with OFDM is widely used in communication systems and it enhances communication performance of the system. There are different methods to enhance the performance of OFDM systems, carrier interferometry code is one of them. While, carrier interferometry code increase the performance of the system and also reduces PAPR level. Carrier interferometry codes can be implemented on an OFDM system by using FFT and wavelet. In this paper we investigate the effect of the relay position on the carrier interferometry cooperative OFDM system which uses wavelet transform. The effect of the relay position is investigated over different combiners and relaying strategies. The results show that, relay position effects the performance of the system and optimal location for the relay is right between source and destination.
{"title":"On the Effect of Relay Position in Carrier Interferometry OFDM for Cooperative Diversity by Wavelet Transform","authors":"C. Çiflikli, Bilgin Yazlik","doi":"10.13189/UJME.2019.070413","DOIUrl":"https://doi.org/10.13189/UJME.2019.070413","url":null,"abstract":"In a wireless communication system, cooperative diversity can be used to combat fading effects. In cooperative diversity, the system uses idle antennas, which are located at different locations, as relays. Cooperative communication with OFDM is widely used in communication systems and it enhances communication performance of the system. There are different methods to enhance the performance of OFDM systems, carrier interferometry code is one of them. While, carrier interferometry code increase the performance of the system and also reduces PAPR level. Carrier interferometry codes can be implemented on an OFDM system by using FFT and wavelet. In this paper we investigate the effect of the relay position on the carrier interferometry cooperative OFDM system which uses wavelet transform. The effect of the relay position is investigated over different combiners and relaying strategies. The results show that, relay position effects the performance of the system and optimal location for the relay is right between source and destination.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132894571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.13189/UJME.2019.070403
A. S. Mariawati, N. Wahyuni, M. Fawaid, A. Umyati, M. W. Riesha, H. Iridistadi, Henny
The common problems faced by post-stroke patients are the lack of facility and time for exercise in rehabilitation. This research aims to design upper extremity exercise portable equipment. Basic theory of this product's design is the Active Range of Motion. The design of upper extremity exercise portable equipment (P-RAT) using Nigel Cross's Rational Method. As the result of design, we obtained the best alternative solution for upper extremity exercise portable equipment with 43 cm of length, 11 cm of width and cm of height equipped with rail extensions for 10 cm, 20 cm, and 30 cm extra length, as well as the capability of elevation setting of the rails at 0°, 10°, 20°, and 30°.
{"title":"Designing Portable-repetitive Upper Extremity Arm Trainer for Post-stroke Patients Using Nigel Cross's Rational Method","authors":"A. S. Mariawati, N. Wahyuni, M. Fawaid, A. Umyati, M. W. Riesha, H. Iridistadi, Henny","doi":"10.13189/UJME.2019.070403","DOIUrl":"https://doi.org/10.13189/UJME.2019.070403","url":null,"abstract":"The common problems faced by post-stroke patients are the lack of facility and time for exercise in rehabilitation. This research aims to design upper extremity exercise portable equipment. Basic theory of this product's design is the Active Range of Motion. The design of upper extremity exercise portable equipment (P-RAT) using Nigel Cross's Rational Method. As the result of design, we obtained the best alternative solution for upper extremity exercise portable equipment with 43 cm of length, 11 cm of width and cm of height equipped with rail extensions for 10 cm, 20 cm, and 30 cm extra length, as well as the capability of elevation setting of the rails at 0°, 10°, 20°, and 30°.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133034088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.13189/UJME.2019.070410
Namwoong Kim, H. Cho
This study examines the characteristics of the steering stability performance of a vehicle with varying tire cornering stiffness. The vehicle and its front and rear tire models, which are the basis of simulation, were fabricated using SPMM and Flat Trac, respectively. Tire cornering stiffness of the front and rear wheels was modulated by changing the LKY, one of the scaling coefficients in the tire model. Steering stability performance evaluation is based on frequency response (ISO7401)[1] which can analyze the dynamic characteristics of the vehicle with varying steering input cycle and Steady State Speed (ISO4138)[2] which enables dynamic analysis of the vehicle with varying transient inputs. The results were analyzed by using measurement assessment factors with high correlation with actual stiffness evaluation. As a result of the evaluation, it was confirmed that the steering and stability performance of the vehicle increase when the cornering stiffness of the front wheel is increased and the cornering stiffness of the rear wheel is decreased, which has enabled us to identify the direction of development of real tires. It is expected that this study will be a starting point to improve the efficiency of the research and development to identify the cause of the decline of the running performance of the tires and the way to enhance it.
{"title":"A Study on the Development Direction of a Tire Using Objective Evaluation and Analysis Techniques","authors":"Namwoong Kim, H. Cho","doi":"10.13189/UJME.2019.070410","DOIUrl":"https://doi.org/10.13189/UJME.2019.070410","url":null,"abstract":"This study examines the characteristics of the steering stability performance of a vehicle with varying tire cornering stiffness. The vehicle and its front and rear tire models, which are the basis of simulation, were fabricated using SPMM and Flat Trac, respectively. Tire cornering stiffness of the front and rear wheels was modulated by changing the LKY, one of the scaling coefficients in the tire model. Steering stability performance evaluation is based on frequency response (ISO7401)[1] which can analyze the dynamic characteristics of the vehicle with varying steering input cycle and Steady State Speed (ISO4138)[2] which enables dynamic analysis of the vehicle with varying transient inputs. The results were analyzed by using measurement assessment factors with high correlation with actual stiffness evaluation. As a result of the evaluation, it was confirmed that the steering and stability performance of the vehicle increase when the cornering stiffness of the front wheel is increased and the cornering stiffness of the rear wheel is decreased, which has enabled us to identify the direction of development of real tires. It is expected that this study will be a starting point to improve the efficiency of the research and development to identify the cause of the decline of the running performance of the tires and the way to enhance it.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114744458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.13189/UJME.2019.070404
S. Ayob, Nor Alisa Mohd Damanhuri
In this paper, a numerical approximation of the stress equation for the indentation of granular materials by a smooth rigid wedge is presented. Plane strain conditions are assumed, and the materials obey the Mohr-Coulomb yield condition. This method determines the deformation of granular material under a smooth rigid wedge punch and construction of stress field in the deforming region which are presented by using MATLAB programme. The granular material is assumed to be in dense, solid like state. The solution only refers to the initial motion after the punch. This was then applied on one type of boundary value problem. By using MATLAB, the value of each point (x,y) and the stress variables (p,ψ) which construct the deformation field are calculated. This method provides simple and reliable algorithms for the solution of the deformation problems involving the stress variables. The results will consequently help in the improvement of the existing labs and experimental facilities in the industries and will eventually increase its efficiency.
{"title":"Numerical Approximation of Plane Deformation for the Indentation of Granular Material by a Smooth Rigid Wedge Punch","authors":"S. Ayob, Nor Alisa Mohd Damanhuri","doi":"10.13189/UJME.2019.070404","DOIUrl":"https://doi.org/10.13189/UJME.2019.070404","url":null,"abstract":"In this paper, a numerical approximation of the stress equation for the indentation of granular materials by a smooth rigid wedge is presented. Plane strain conditions are assumed, and the materials obey the Mohr-Coulomb yield condition. This method determines the deformation of granular material under a smooth rigid wedge punch and construction of stress field in the deforming region which are presented by using MATLAB programme. The granular material is assumed to be in dense, solid like state. The solution only refers to the initial motion after the punch. This was then applied on one type of boundary value problem. By using MATLAB, the value of each point (x,y) and the stress variables (p,ψ) which construct the deformation field are calculated. This method provides simple and reliable algorithms for the solution of the deformation problems involving the stress variables. The results will consequently help in the improvement of the existing labs and experimental facilities in the industries and will eventually increase its efficiency.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129994863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The methodology of creation of automatic control system (ACS) of water level in the steam generator is developed. The mathematical model of checking its working capacity is developed, which allows establishing the maximum deviations of water level without carrying out full-scale tests, without adjusting the settings of tripping actuation according to the water level in the drum. The foreign methods of PID-regulator adjustment in the cascade system of automatic water level control in the boiler drum are considered, on the basis of which an invariant cascade system of automatic control is proposed. The invariant Cascade-System of Automatic Control (CSAC) of water level in a boiler drum is offered. Simulation results of the invariant cascade-system of automatic control in comparison with CSAC, configured with best foreign method, showed a significant improvement in the quality of regulation in all the major disturbing influences. The results can be used in the development of adaptive control systems and other thermal power devices.
{"title":"Mathematical Modeling of Transient Processes of the Automatic Control System of Water Level in the Steam Generator","authors":"Siddikov Isamiddin Xakimovich, Umurzakova Dilnoza Maxamadjonovna","doi":"10.13189/UJME.2019.070401","DOIUrl":"https://doi.org/10.13189/UJME.2019.070401","url":null,"abstract":"The methodology of creation of automatic control system (ACS) of water level in the steam generator is developed. The mathematical model of checking its working capacity is developed, which allows establishing the maximum deviations of water level without carrying out full-scale tests, without adjusting the settings of tripping actuation according to the water level in the drum. The foreign methods of PID-regulator adjustment in the cascade system of automatic water level control in the boiler drum are considered, on the basis of which an invariant cascade system of automatic control is proposed. The invariant Cascade-System of Automatic Control (CSAC) of water level in a boiler drum is offered. Simulation results of the invariant cascade-system of automatic control in comparison with CSAC, configured with best foreign method, showed a significant improvement in the quality of regulation in all the major disturbing influences. The results can be used in the development of adaptive control systems and other thermal power devices.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116330483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.13189/UJME.2019.070405
K. Hamzah, N. N. Long, N. Senu, Z. Eshkuvatov, Ilias
The modified complex variable function method with the continuity conditions of the resultant force and displacement function are used to formulate the hypersingular integral equations (HSIE) for an inclined crack and a circular arc crack lies in the upper part of bonded dissimilar materials subjected to various remote stresses. The curve length coordinate method and appropriate quadrature formulas are used to solve numerically the unknown crack opening displacement (COD) function and the traction along the crack as the right hand term of HSIE. The obtained COD is then used to compute the stress intensity factors (SIF), which control the stability behavior of bodies or materials containing cracks or flaws. Numerical results showed the behavior of the nondimensional SIF at the crack tips. It is observed that the nondimensional SIF at the crack tips depend on the various remote stresses, the elastic constants ratio, the crack geometries and the distance between the crack and the boundary.
{"title":"Stress Intensity Factors for a Crack in Bonded Dissimilar Materials Subjected to Various Stresses","authors":"K. Hamzah, N. N. Long, N. Senu, Z. Eshkuvatov, Ilias","doi":"10.13189/UJME.2019.070405","DOIUrl":"https://doi.org/10.13189/UJME.2019.070405","url":null,"abstract":"The modified complex variable function method with the continuity conditions of the resultant force and displacement function are used to formulate the hypersingular integral equations (HSIE) for an inclined crack and a circular arc crack lies in the upper part of bonded dissimilar materials subjected to various remote stresses. The curve length coordinate method and appropriate quadrature formulas are used to solve numerically the unknown crack opening displacement (COD) function and the traction along the crack as the right hand term of HSIE. The obtained COD is then used to compute the stress intensity factors (SIF), which control the stability behavior of bodies or materials containing cracks or flaws. Numerical results showed the behavior of the nondimensional SIF at the crack tips. It is observed that the nondimensional SIF at the crack tips depend on the various remote stresses, the elastic constants ratio, the crack geometries and the distance between the crack and the boundary.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128848214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.13189/UJME.2019.070402
F. Farhatnia, M. Sarami
This is the first attempt to utilize the refined zigzag theory (RZT) to study the bending and buckling behavior of a functional graded (metal/ceramic) thick beam. RZT, which has been exploited for the analysis of multilayered composite and sandwich beams does not employ shear correction factor. Furthermore, the number of kinematics variables of the RZT is not dependent to the number of layers in comparison with the layerwise theory. With regarding to the numerical solution, RZT, also requires C0 continuity interpolation, which leads to the development of this theory in finite element method. It is assumed that the mechanical properties of the beam varies through the thickness. According to the volume fraction of metal and ceramic, it is discretized across the thickness; consequently, the functionally graded beam (FGB) is modeled as a multi-layered one. The beam subjected to uniformly transverse and axial loadings. The equilibrium equations are established using the principle of virtual work. Using the shape functions of the first and second order forms, the non-isoparametric finite element consisting of three nodes and nine degrees of freedom are extracted. To confirm the excellent accuracy of the present approach, some numerical examples are provided and compared with those available in the literature that reveals that RZT is a trusty and validated theory to analyze the FG thick beams.
{"title":"Finite Element Approach of Bending and Buckling Analysis of FG Beams Based on Refined Zigzag Theory","authors":"F. Farhatnia, M. Sarami","doi":"10.13189/UJME.2019.070402","DOIUrl":"https://doi.org/10.13189/UJME.2019.070402","url":null,"abstract":"This is the first attempt to utilize the refined zigzag theory (RZT) to study the bending and buckling behavior of a functional graded (metal/ceramic) thick beam. RZT, which has been exploited for the analysis of multilayered composite and sandwich beams does not employ shear correction factor. Furthermore, the number of kinematics variables of the RZT is not dependent to the number of layers in comparison with the layerwise theory. With regarding to the numerical solution, RZT, also requires C0 continuity interpolation, which leads to the development of this theory in finite element method. It is assumed that the mechanical properties of the beam varies through the thickness. According to the volume fraction of metal and ceramic, it is discretized across the thickness; consequently, the functionally graded beam (FGB) is modeled as a multi-layered one. The beam subjected to uniformly transverse and axial loadings. The equilibrium equations are established using the principle of virtual work. Using the shape functions of the first and second order forms, the non-isoparametric finite element consisting of three nodes and nine degrees of freedom are extracted. To confirm the excellent accuracy of the present approach, some numerical examples are provided and compared with those available in the literature that reveals that RZT is a trusty and validated theory to analyze the FG thick beams.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124739739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.13189/UJME.2019.070409
N. Khashi’ie, N. Arifin, E. Hafidzuddin, N. Wahi, M. R. Ilias
The present study utilized Cattaneo-Christov heat flux model for solving nanofluid flow and heat transfer towards a vertical stretching sheet with the presence of magnetic field and double stratification. Thermal and solutal buoyancy forces are also examined to deal with the double stratification effects. Buongiorno's model of nanofluid is used to incorporate the effects of Brownian motion and thermophoresis. The boundary layer with non-Fourier energy equations are reduced into a system of nonlinear ordinary (similarity) differential equations using suitable transformations and then numerically solved using bvp4c solver in MATLAB software. The local Nusselt and Sherwood numbers of few limited cases are tabulated and compared with the earlier published works. It showed that a positive agreement was found with the previous study and thus, validated the present method. Numerical solutions are graphically demonstrated for several parameters namely magnetic, thermal relaxation, stratifications (thermal and solutal), thermophoresis and Brownian motion on the velocity, temperature and nanoparticles volume fraction profiles. An upsurge of the heat transfer rate was observed with the imposition of the thermal relaxation parameter (Cattaneo-Christov model) whereas the accretion of thermal and solutal stratification parameters reduced the temperature and nanoparticles concentration profiles, respectively.
{"title":"Magnetohydrodynamics (MHD) Flow and Heat Transfer of a Doubly Stratified Nanofluid Using Cattaneo-Christov Model","authors":"N. Khashi’ie, N. Arifin, E. Hafidzuddin, N. Wahi, M. R. Ilias","doi":"10.13189/UJME.2019.070409","DOIUrl":"https://doi.org/10.13189/UJME.2019.070409","url":null,"abstract":"The present study utilized Cattaneo-Christov heat flux model for solving nanofluid flow and heat transfer towards a vertical stretching sheet with the presence of magnetic field and double stratification. Thermal and solutal buoyancy forces are also examined to deal with the double stratification effects. Buongiorno's model of nanofluid is used to incorporate the effects of Brownian motion and thermophoresis. The boundary layer with non-Fourier energy equations are reduced into a system of nonlinear ordinary (similarity) differential equations using suitable transformations and then numerically solved using bvp4c solver in MATLAB software. The local Nusselt and Sherwood numbers of few limited cases are tabulated and compared with the earlier published works. It showed that a positive agreement was found with the previous study and thus, validated the present method. Numerical solutions are graphically demonstrated for several parameters namely magnetic, thermal relaxation, stratifications (thermal and solutal), thermophoresis and Brownian motion on the velocity, temperature and nanoparticles volume fraction profiles. An upsurge of the heat transfer rate was observed with the imposition of the thermal relaxation parameter (Cattaneo-Christov model) whereas the accretion of thermal and solutal stratification parameters reduced the temperature and nanoparticles concentration profiles, respectively.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129278823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.13189/UJME.2019.070411
I. Singh, K. Goyal, R. Goyal
Different coating with varying quantities of Al2O3 and ZrO2 were fabricated on the SA213 T-91 steel using plasma spray method to study hot corrosion resistance behavior. Experiment was conducted under the molten salt environment of 60% Na2SO4-40%V2O5 at a temperature of 900℃ inside a furnace for 50 cycles. Each cycle consisted of 1hr heating and 20 min cooling at room temperature. Results were examined using the visual inspection, weight change measurement, X-ray diffraction technique and Scanning Electron Microscopy/ Energy Dispersive X-Ray Spectroscopy (SEM/ EDS) analysis. Results showed that uncoated T-91 steel was more prone to hot corrosion as compared to coated steel specimens. It was noticed that ZrO2 reinforcements in Al2O3 coating matrix helped to enhance corrosion resistance of these coatings. The corrosion resistance increased with increase in ZrO2 content in coating matrix.
{"title":"Evaluations of Hot Corrosion Behavior of Al2O3 Thermal Spray Coatings with ZrO2 Reinforcements on T-91 Steel","authors":"I. Singh, K. Goyal, R. Goyal","doi":"10.13189/UJME.2019.070411","DOIUrl":"https://doi.org/10.13189/UJME.2019.070411","url":null,"abstract":"Different coating with varying quantities of Al2O3 and ZrO2 were fabricated on the SA213 T-91 steel using plasma spray method to study hot corrosion resistance behavior. Experiment was conducted under the molten salt environment of 60% Na2SO4-40%V2O5 at a temperature of 900℃ inside a furnace for 50 cycles. Each cycle consisted of 1hr heating and 20 min cooling at room temperature. Results were examined using the visual inspection, weight change measurement, X-ray diffraction technique and Scanning Electron Microscopy/ Energy Dispersive X-Ray Spectroscopy (SEM/ EDS) analysis. Results showed that uncoated T-91 steel was more prone to hot corrosion as compared to coated steel specimens. It was noticed that ZrO2 reinforcements in Al2O3 coating matrix helped to enhance corrosion resistance of these coatings. The corrosion resistance increased with increase in ZrO2 content in coating matrix.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126442166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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