Pub Date : 2020-05-01DOI: 10.13189/ujme.2020.080301
N. H. Son, D. Trung
This paper presents the optimization of cutting parameters when surface milling according to the stages of the response surface method. The implemented stages of the response surface method include the screening design, initial experiments and response surface design. The objective of the screening design is to select the input parameters for the next experimental stages. The goal of the initial experiments is to check the choice range of the input parameters ensures that the output function is extreme point or not. The aim of response surface design is to build the relationship between output parameters and the input parameters. The machined material in this study is C45 steel, while the used cutting tool is the face mill with PVD-coated inserts. Accordingly, the optimal values of cutting parameters including cutting speed, feed rate and depth of cut are determined at 230 (m/min), 0.23 (mm/toolpath) and 0.888 (mm), respectively. In case of machining with this cutting parameter, the surface roughness of workpiece reaches the smallest value, only about 0.15 µm.
{"title":"Optimization of Cutting Parameters When Surface Milling with Face Milling Tool According to the Stages of Response Surface Method","authors":"N. H. Son, D. Trung","doi":"10.13189/ujme.2020.080301","DOIUrl":"https://doi.org/10.13189/ujme.2020.080301","url":null,"abstract":"This paper presents the optimization of cutting parameters when surface milling according to the stages of the response surface method. The implemented stages of the response surface method include the screening design, initial experiments and response surface design. The objective of the screening design is to select the input parameters for the next experimental stages. The goal of the initial experiments is to check the choice range of the input parameters ensures that the output function is extreme point or not. The aim of response surface design is to build the relationship between output parameters and the input parameters. The machined material in this study is C45 steel, while the used cutting tool is the face mill with PVD-coated inserts. Accordingly, the optimal values of cutting parameters including cutting speed, feed rate and depth of cut are determined at 230 (m/min), 0.23 (mm/toolpath) and 0.888 (mm), respectively. In case of machining with this cutting parameter, the surface roughness of workpiece reaches the smallest value, only about 0.15 µm.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126634390","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 : 2020-05-01DOI: 10.13189/ujme.2020.080302
W. Rauf, R. Tarakka, Jalaluddin Jalaluddin, M. Ihsan
Flow separation is expected to have the effect of increasing aerodynamic drag due to decreased pressure distribution at the rear of the vehicle. The faster the flow separation occurs, the lower the pressure distribution is in the area, thereby reducing vehicle performance. Therefore, flow modification is needed with expected effects on the separation delay and the reduction in wake and vortex formation. This modification can be done through the application of suction active control in the separation area. The research is intended to analyze the effect of suction active control on flow characteristics, pressure distribution and aerodynamic drag on vehicle models with suction velocity variations. The test model used is an Ahmed model modified by changing the orientation of the flow. The study used a numerical computational approach with a standard k-epsilon turbulence model at 19.4 m/s upstream velocity. Results revealed that the use of flow active control was able to reduce wake and vortex formation through separation delay and to increase the minimum pressure coefficient by 73% on the model with Usc2 suction velocity of 0.5 m/s, gaining the highest drag coefficient reduction of 10.897% in the same model.
{"title":"Effect of Flow Separation Control with Suction Velocity Variation: Study of Flow Characteristics, Pressure Coefficient, and Drag Coefficient","authors":"W. Rauf, R. Tarakka, Jalaluddin Jalaluddin, M. Ihsan","doi":"10.13189/ujme.2020.080302","DOIUrl":"https://doi.org/10.13189/ujme.2020.080302","url":null,"abstract":"Flow separation is expected to have the effect of increasing aerodynamic drag due to decreased pressure distribution at the rear of the vehicle. The faster the flow separation occurs, the lower the pressure distribution is in the area, thereby reducing vehicle performance. Therefore, flow modification is needed with expected effects on the separation delay and the reduction in wake and vortex formation. This modification can be done through the application of suction active control in the separation area. The research is intended to analyze the effect of suction active control on flow characteristics, pressure distribution and aerodynamic drag on vehicle models with suction velocity variations. The test model used is an Ahmed model modified by changing the orientation of the flow. The study used a numerical computational approach with a standard k-epsilon turbulence model at 19.4 m/s upstream velocity. Results revealed that the use of flow active control was able to reduce wake and vortex formation through separation delay and to increase the minimum pressure coefficient by 73% on the model with Usc2 suction velocity of 0.5 m/s, gaining the highest drag coefficient reduction of 10.897% in the same model.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131882901","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 : 2020-03-01DOI: 10.13189/ujme.2020.080204
Q. Nguyen, The-Vinh Do, Thi-Nguyen Nguyen
The heat generated during metal cutting is a major factor affecting the cutting forces, tool life, and chip formation mode. In this research, the Taguchi method was applied to find the optimal values of cutting parameters in hard milling of SKD 61 steel to minimize cutting temperature under cutting oil and Al2O3 nanofluid - MQL condition. The effects of cutting parameters including cutting speed, feed rate and depth of cut were investigated by using an L9 array of Taguchi method. The signal-to-noise (S/N) ratios and analysis of variance (ANOVA) were applied to analyze the influence of input factors on the cutting temperature. The study result shows that cutting speed is the most influential factor, which gives statistic significant effect on cutting temperature. The speed contributes 52.55 % of total effect under cooling condition of MQL with cutting oil and 53.77 % of total effect under cooling condition of MQL with Al2O3 nanofluid. Additionally, the effectiveness in cutting heat reduction of cutting oil - MQL was compared with Al2O3 nanofluid - MQL based on experimental measurement of cutting temperature. According to the analysis, the Al2O3 nanofluid – MQL is a better option for the cooling conditions during hard milling of SKD 61 steel.
{"title":"Minimization of Temperature in Cutting Zone: A Case Study of Hard Milling of SKD 61 Steel","authors":"Q. Nguyen, The-Vinh Do, Thi-Nguyen Nguyen","doi":"10.13189/ujme.2020.080204","DOIUrl":"https://doi.org/10.13189/ujme.2020.080204","url":null,"abstract":"The heat generated during metal cutting is a major factor affecting the cutting forces, tool life, and chip formation mode. In this research, the Taguchi method was applied to find the optimal values of cutting parameters in hard milling of SKD 61 steel to minimize cutting temperature under cutting oil and Al2O3 nanofluid - MQL condition. The effects of cutting parameters including cutting speed, feed rate and depth of cut were investigated by using an L9 array of Taguchi method. The signal-to-noise (S/N) ratios and analysis of variance (ANOVA) were applied to analyze the influence of input factors on the cutting temperature. The study result shows that cutting speed is the most influential factor, which gives statistic significant effect on cutting temperature. The speed contributes 52.55 % of total effect under cooling condition of MQL with cutting oil and 53.77 % of total effect under cooling condition of MQL with Al2O3 nanofluid. Additionally, the effectiveness in cutting heat reduction of cutting oil - MQL was compared with Al2O3 nanofluid - MQL based on experimental measurement of cutting temperature. According to the analysis, the Al2O3 nanofluid – MQL is a better option for the cooling conditions during hard milling of SKD 61 steel.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114376415","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 : 2020-03-01DOI: 10.13189/ujme.2020.080203
N. Thien, D. Trung, L. Ky, Le Hoang Anh
This paper presents a study of the roughness prediction of the workpiece when using CBN (Cubic Boron Nitride) grinding wheel to process C45 steel on a surface grinder. On the basis of inheriting the previously published studies on modeling surface roughness of workpiece when grinding, this study was conducted to develop one of these models and build a new model of surface roughness that consider many factors affecting surface roughness. Cutting parameters, parameters of grinding wheel, characteristics of materials, characteristics of contact of grinding wheel with workpiece have been included in the roughness model of the surface roughness of workpiece. This new surface roughness model was used to predict surface roughness of workpiece when grinding C45 steel with CBN grinding wheel. The results showed that the surface roughness value when predicting was very suitable for the experiment and the average deviation between the predicted results and the experimental results was only about 9.84%. The surface roughness model proposed in this study also confirms that the roughness can be predicted more accurately than the previous surface roughness models. And then, the development direction for further research is also mentioned in this paper.
{"title":"Prediction of Surface Roughness When Surface Grinding C45 Steel Using CBN Grinding Wheel","authors":"N. Thien, D. Trung, L. Ky, Le Hoang Anh","doi":"10.13189/ujme.2020.080203","DOIUrl":"https://doi.org/10.13189/ujme.2020.080203","url":null,"abstract":"This paper presents a study of the roughness prediction of the workpiece when using CBN (Cubic Boron Nitride) grinding wheel to process C45 steel on a surface grinder. On the basis of inheriting the previously published studies on modeling surface roughness of workpiece when grinding, this study was conducted to develop one of these models and build a new model of surface roughness that consider many factors affecting surface roughness. Cutting parameters, parameters of grinding wheel, characteristics of materials, characteristics of contact of grinding wheel with workpiece have been included in the roughness model of the surface roughness of workpiece. This new surface roughness model was used to predict surface roughness of workpiece when grinding C45 steel with CBN grinding wheel. The results showed that the surface roughness value when predicting was very suitable for the experiment and the average deviation between the predicted results and the experimental results was only about 9.84%. The surface roughness model proposed in this study also confirms that the roughness can be predicted more accurately than the previous surface roughness models. And then, the development direction for further research is also mentioned in this paper.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133950998","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 : 2020-03-01DOI: 10.13189/ujme.2020.080205
Abderrahim Razouki, L. Boutahar, K. E. Bikri
The aim of this work is to study the static bending of functionally graded beams accounting higher order of shear deformation theory. The governing equations, derived from the virtual work principle, are a set of ordinary differential equations describing a static bending of a thick beam. Thus, this paper presents the differential transform method used to solve the previous system of equations. The results obtained lay the foundation to determine the exact analytical solution for different boundary conditions and external loadings. The axial displacement and the bending and shear displacements, in the exact analytical form, of a thick clamped-clamped beam with functionally graded material under a uniform load will be fully developed. Moreover, normal and shear stresses will be analyzed. To confirm the efficiency of this work, a comparison with the numerical results provided by literature is performed. Through this work, the given analytical results provide engineers with an accurate tool to determine the analytical solution for the bending of plates and shells. In addition, the geometric and material parameters that appear clearly in the analytical results allow for a more optimized design of functionally graded material beams. This type of beams is frequently used in mechanical engineering fields such as aerospace engineering.
{"title":"A New Method of Resolution of the Bending of Thick FGM Beams Based on Refined Higher Order Shear Deformation Theory","authors":"Abderrahim Razouki, L. Boutahar, K. E. Bikri","doi":"10.13189/ujme.2020.080205","DOIUrl":"https://doi.org/10.13189/ujme.2020.080205","url":null,"abstract":"The aim of this work is to study the static bending of functionally graded beams accounting higher order of shear deformation theory. The governing equations, derived from the virtual work principle, are a set of ordinary differential equations describing a static bending of a thick beam. Thus, this paper presents the differential transform method used to solve the previous system of equations. The results obtained lay the foundation to determine the exact analytical solution for different boundary conditions and external loadings. The axial displacement and the bending and shear displacements, in the exact analytical form, of a thick clamped-clamped beam with functionally graded material under a uniform load will be fully developed. Moreover, normal and shear stresses will be analyzed. To confirm the efficiency of this work, a comparison with the numerical results provided by literature is performed. Through this work, the given analytical results provide engineers with an accurate tool to determine the analytical solution for the bending of plates and shells. In addition, the geometric and material parameters that appear clearly in the analytical results allow for a more optimized design of functionally graded material beams. This type of beams is frequently used in mechanical engineering fields such as aerospace engineering.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134163454","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 : 2020-03-01DOI: 10.13189/ujme.2020.080201
P. Krishna, A. Jaware, R. Srikant
Friction stir welding (FSW) is a solid-state welding process that is gaining importance in recent times due to better control of microstructure. In the present work, a thermo-mechanical model is developed for FSW and under water friction stir welding (UFSW) of AA 6063-T6. Temperature dependent viscosity is considered as thermo physical property along with constant values of thermal conductivity and specific heat. Fine mesh is used for complex parts of tool to obtain good results. Rotational speed of tool, feed rate and plunge pressure are taken as influencing parameters for study. Partial stick-slip boundary condition is taken between the tool and work piece interfaces. Experiments were carried out for validation of model. The results of thermal and material flow histories are extracted. Results shows the significant differences in peak temperature of FSW and UFSW along with reduction in heat affected zone in UFSW whereas results of material flow velocity underlined the differences between the FSW and UFSW in term of peak values of stir velocities with the change in influencing parameters.
{"title":"Modelling and Simulation of Friction Stir Welding and Under Water Friction Stir Welding of Al6063 Alloy","authors":"P. Krishna, A. Jaware, R. Srikant","doi":"10.13189/ujme.2020.080201","DOIUrl":"https://doi.org/10.13189/ujme.2020.080201","url":null,"abstract":"Friction stir welding (FSW) is a solid-state welding process that is gaining importance in recent times due to better control of microstructure. In the present work, a thermo-mechanical model is developed for FSW and under water friction stir welding (UFSW) of AA 6063-T6. Temperature dependent viscosity is considered as thermo physical property along with constant values of thermal conductivity and specific heat. Fine mesh is used for complex parts of tool to obtain good results. Rotational speed of tool, feed rate and plunge pressure are taken as influencing parameters for study. Partial stick-slip boundary condition is taken between the tool and work piece interfaces. Experiments were carried out for validation of model. The results of thermal and material flow histories are extracted. Results shows the significant differences in peak temperature of FSW and UFSW along with reduction in heat affected zone in UFSW whereas results of material flow velocity underlined the differences between the FSW and UFSW in term of peak values of stir velocities with the change in influencing parameters.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"22 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130964967","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 : 2020-03-01DOI: 10.13189/ujme.2020.080206
Le Ngoc Truc, Nguyễn Tuấn Nghĩa, N. Thanh, Nguyễn Minh Thiện, T. Nguyen
Actuator faults of robot manipulators may occur during their lifetime after long time in operation. There are several kinds of actuator failures such as locked joints, free-swinging joints, and loss of actuator torque effectiveness. The main goals of this paper are (i) to classify the loss of torque effectiveness, called torque degradation, into three divergent cases: Boundary Degradation of Torque (BDT), Boundary Degradation of Torque Rate (BDTR), and Proportional Degradation of Torque (PDT); and (ii) to analyze their effect on behavior of a typical industrial robot. The possible failures might degrade the whole system performance or in some certain cases leading to unavoidable damages. In normal operation, we do not have a controller designed specifically for these faults. In order to have a better understanding on how the mentioned problems affect robot operations, with an assumption that the knowledge of robot parameters are known, a closed-loop control law is used to demonstrate the control ability in dealing with these cases. By taking advantage of MATLAB/Simscape Multibody, the quasi-physical model of robot is employed instead of expensive prototypes and experiments. Simulation results show that the joint responses according to different types of failures. In many cases, the robot cannot track the reference trajectories properly.
{"title":"Effect of Actuator Torque Degradation on Behavior of a 6-DOF Industrial Robot","authors":"Le Ngoc Truc, Nguyễn Tuấn Nghĩa, N. Thanh, Nguyễn Minh Thiện, T. Nguyen","doi":"10.13189/ujme.2020.080206","DOIUrl":"https://doi.org/10.13189/ujme.2020.080206","url":null,"abstract":"Actuator faults of robot manipulators may occur during their lifetime after long time in operation. There are several kinds of actuator failures such as locked joints, free-swinging joints, and loss of actuator torque effectiveness. The main goals of this paper are (i) to classify the loss of torque effectiveness, called torque degradation, into three divergent cases: Boundary Degradation of Torque (BDT), Boundary Degradation of Torque Rate (BDTR), and Proportional Degradation of Torque (PDT); and (ii) to analyze their effect on behavior of a typical industrial robot. The possible failures might degrade the whole system performance or in some certain cases leading to unavoidable damages. In normal operation, we do not have a controller designed specifically for these faults. In order to have a better understanding on how the mentioned problems affect robot operations, with an assumption that the knowledge of robot parameters are known, a closed-loop control law is used to demonstrate the control ability in dealing with these cases. By taking advantage of MATLAB/Simscape Multibody, the quasi-physical model of robot is employed instead of expensive prototypes and experiments. Simulation results show that the joint responses according to different types of failures. In many cases, the robot cannot track the reference trajectories properly.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124577426","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 : 2020-03-01DOI: 10.13189/ujme.2020.080207
N. Anh, H. T. Binh, T. V. Thắng
The turning radius of the vehicle is determined based on the coordinates of the center of gravity. When the vehicle is moving at different velocities and driving at different steering angles, the value of the turning radius is also different. This change is nonlinear and continuous and determined by simulation or experimentation process. Previous studies have not established the formula to calculate the value of a turning radius of the vehicle based on input parameters. Therefore, determining the value of a turning radius is complex and time-consuming. This research has shown the dependence between turning radius R on input parameters such as velocity v and steering angle by using a double-track dynamic vehicle model to simulate. Besides, this research also established the state function to calculate the turning radius of the vehicle at different velocities and steering angles. The state function is determined based on the rule of change of the corresponding values. Using only the determined input parameters like velocity and steering angle, the value of the turning radius can be easily calculated with high accuracy through 4 steps. The reference coefficients needed to calculate are also provided in this research. The results of the research can be applied in various computational conditions.
{"title":"Establishing the State Function to Determine the Turning Radius of the Vehicle When Steering","authors":"N. Anh, H. T. Binh, T. V. Thắng","doi":"10.13189/ujme.2020.080207","DOIUrl":"https://doi.org/10.13189/ujme.2020.080207","url":null,"abstract":"The turning radius of the vehicle is determined based on the coordinates of the center of gravity. When the vehicle is moving at different velocities and driving at different steering angles, the value of the turning radius is also different. This change is nonlinear and continuous and determined by simulation or experimentation process. Previous studies have not established the formula to calculate the value of a turning radius of the vehicle based on input parameters. Therefore, determining the value of a turning radius is complex and time-consuming. This research has shown the dependence between turning radius R on input parameters such as velocity v and steering angle by using a double-track dynamic vehicle model to simulate. Besides, this research also established the state function to calculate the turning radius of the vehicle at different velocities and steering angles. The state function is determined based on the rule of change of the corresponding values. Using only the determined input parameters like velocity and steering angle, the value of the turning radius can be easily calculated with high accuracy through 4 steps. The reference coefficients needed to calculate are also provided in this research. The results of the research can be applied in various computational conditions.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121197102","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 : 2020-03-01DOI: 10.13189/ujme.2020.080202
M. Sulaiman, A. Adham, Sirwan Farooq Omar
In this study, nanofluids were used as coolant for high-heat dissipation electronic devices with nanoparticle volume concentrations from 1% to 5%. The results were compared to other conventional cooling systems. Graphite-H2O and CuO-H2O nanofluids were analyzed at inlet velocities of 0.1 m/s and 1.5 m/s in a rectangular copper shaped microchannel heat sink MCHS with a bottom size of 20mm×20mm. The results indicate that suspended nanoparticles significantly increase thermal conductivity, heat flux, pumping power, and pressure drop. For graphite-water and CuO-water nanofluids at 0.1m/s with 5.0% volume, the greatest percentage increase in thermal conductivity was 15.52% and 14.34%, respectively. Graphite-water at 0.1 m/s and 1.5 m/s with 5% volume fraction had a maximum heat flux of 18% and 3.46%, respectively. CuO-water at 0.1 m/s and 1.5 m/s inlet velocity with the same volume concentrations had a heat flux of 17.83% and 3.33%, respectively. For graphite-H2O and CuO-H2O at 0.1 m/s with 5% volume fraction, pumping power and pressure drop were 0.000695 W and 92.63 Pa, respectively. For inlet velocity of 1.5 m/s with same volume concentration were 0.156306 W and 1389.39 Pa, respectively.
{"title":"Thermal and Hydrodynamic Characteristics of Graphite-H2O and CuO-H2O Nanofluids in Microchannel Heat Sinks","authors":"M. Sulaiman, A. Adham, Sirwan Farooq Omar","doi":"10.13189/ujme.2020.080202","DOIUrl":"https://doi.org/10.13189/ujme.2020.080202","url":null,"abstract":"In this study, nanofluids were used as coolant for high-heat dissipation electronic devices with nanoparticle volume concentrations from 1% to 5%. The results were compared to other conventional cooling systems. Graphite-H2O and CuO-H2O nanofluids were analyzed at inlet velocities of 0.1 m/s and 1.5 m/s in a rectangular copper shaped microchannel heat sink MCHS with a bottom size of 20mm×20mm. The results indicate that suspended nanoparticles significantly increase thermal conductivity, heat flux, pumping power, and pressure drop. For graphite-water and CuO-water nanofluids at 0.1m/s with 5.0% volume, the greatest percentage increase in thermal conductivity was 15.52% and 14.34%, respectively. Graphite-water at 0.1 m/s and 1.5 m/s with 5% volume fraction had a maximum heat flux of 18% and 3.46%, respectively. CuO-water at 0.1 m/s and 1.5 m/s inlet velocity with the same volume concentrations had a heat flux of 17.83% and 3.33%, respectively. For graphite-H2O and CuO-H2O at 0.1 m/s with 5% volume fraction, pumping power and pressure drop were 0.000695 W and 92.63 Pa, respectively. For inlet velocity of 1.5 m/s with same volume concentration were 0.156306 W and 1389.39 Pa, respectively.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134096985","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 : 2020-01-01DOI: 10.13189/ujme.2020.080104
N. H. Son, D. Trung, N. Nguyen
This paper presents a new approach to improve the machining productivity when grinding the SKD11 steel by using CBN grinding wheel. This approach based on the satisfaction of the surface roughness requirement. The grinding experiments were carried out according to Box-Behnken plan by using the CBN grinding wheel, HY-180x13x31.75-100#. The experimental data was used to build a regression function of the surface roughness depending of the cutting parameters in grinding process including the workpiece velocity, radial feed rate, and depth of cut. The effect degree of each cutting parameter on the surface roughness was also determined. And then, a new solution was proposed to improve the grinding productivity by increasing the workpiece velocity with the satisfaction of the surface roughness requirement. The proposed solution was verified by experimental research. The analyzed results showed that the workpiece velocity can be increased about 1.7 times to increase the machining productivity while the surface roughness only changed about 0.14μm.
{"title":"A Study on Productivity Improvement for the SKD11 Steel Grinding by Using CBN Grinding Wheel - A New Approach","authors":"N. H. Son, D. Trung, N. Nguyen","doi":"10.13189/ujme.2020.080104","DOIUrl":"https://doi.org/10.13189/ujme.2020.080104","url":null,"abstract":"This paper presents a new approach to improve the machining productivity when grinding the SKD11 steel by using CBN grinding wheel. This approach based on the satisfaction of the surface roughness requirement. The grinding experiments were carried out according to Box-Behnken plan by using the CBN grinding wheel, HY-180x13x31.75-100#. The experimental data was used to build a regression function of the surface roughness depending of the cutting parameters in grinding process including the workpiece velocity, radial feed rate, and depth of cut. The effect degree of each cutting parameter on the surface roughness was also determined. And then, a new solution was proposed to improve the grinding productivity by increasing the workpiece velocity with the satisfaction of the surface roughness requirement. The proposed solution was verified by experimental research. The analyzed results showed that the workpiece velocity can be increased about 1.7 times to increase the machining productivity while the surface roughness only changed about 0.14μm.","PeriodicalId":275027,"journal":{"name":"Universal Journal of Mechanical Engineering","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128664303","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：