Pub Date : 2019-01-23DOI: 10.24321/2349.7661.201803
Sudeshna Ghosh
This paper numerically demonstrates the Drafting, Kissing and Tumbling (DKT) phenomenon between two interacting circular, impermeable particles with same Diameter (D) but with di?erent densities in a confined medium using Immersed Boundary (IB) method in two-dimensions. Two cases were considered for this particular scenario, Case 1 where the trailing particle’s density is considered higher than the leading particle and in Case 2 it is vice-versa. In Case 1, the particles undergo DKT phase. But the pattern observed is not uniform for all density di?erences. For some values of density di?erences, the particles experience one phase of DKT and for some other values of density di?erences, the particles experience two phase of DKT. In Case 2, for some values of density di?erences they part away from each other without experiencing DKT process and for some other values they experience DKT. The paper has further studied the e?ect of the vertical initial distance between two interacting particles for a specific density di?erence. For the range of initial vertical distance [2D, 4D] chosen, it was observed that the hydrodynamic interaction (in terms of DKT) between the particles remain the same irrespective of the initial vertical distance. The paper in the end performed convergence studies. Settling velocities of the particles was chosen as representative for determining convergence rate. The study done suggested that the implementation of the IB method is close to the expected first-order accuracy in space.
{"title":"Study of Drafting, Kissing and Tumbling Process of two Particles with different Densities using Immersed Boundary Method in a Confined Medium","authors":"Sudeshna Ghosh","doi":"10.24321/2349.7661.201803","DOIUrl":"https://doi.org/10.24321/2349.7661.201803","url":null,"abstract":"This paper numerically demonstrates the Drafting, Kissing and Tumbling (DKT) phenomenon between two interacting circular, impermeable particles with same Diameter (D) but with di?erent densities in a confined medium using Immersed Boundary (IB) method in two-dimensions. Two cases were considered for this particular scenario, Case 1 where the trailing particle’s density is considered higher than the leading particle and in Case 2 it is vice-versa. In Case 1, the particles undergo DKT phase. But the pattern observed is not uniform for all density di?erences. For some values of density di?erences, the particles experience one phase of DKT and for some other values of density di?erences, the particles experience two phase of DKT. In Case 2, for some values of density di?erences they part away from each other without experiencing DKT process and for some other values they experience DKT. The paper has further studied the e?ect of the vertical initial distance between two interacting particles for a specific density di?erence. For the range of initial vertical distance [2D, 4D] chosen, it was observed that the hydrodynamic interaction (in terms of DKT) between the particles remain the same irrespective of the initial vertical distance. The paper in the end performed convergence studies. Settling velocities of the particles was chosen as representative for determining convergence rate. The study done suggested that the implementation of the IB method is close to the expected first-order accuracy in space.","PeriodicalId":412436,"journal":{"name":"Journal of Advanced Research in Applied Mechanics & Computational Fluid Dynamics","volume":"207 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122355992","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 : 2018-07-02DOI: 10.24321/2349.7661.201801
Deepa Chandran
LED’S have been used in many products due to its longevity, more power saving and higher lumens per watt. About 80% of the electrical power is wasted as heat or reductant heat which in turn increases the junction temperature of the LED’s. This increase in the temperature in the LED’S decreases the longevity and color of LED’S. Proper thermal management is required to remove this heat effectively. The heat sink design and usage of proper thermal interface materials for increasing the heat removal is required. In this paper, temperature increase in a LED fixture during a time interval with and without thermal interface material is measured and tabulated to find the effectiveness of the thermal interface material in removing more heat is studied. In addition, a simulation using Solidworks thermal simulation is done to validate the analytical thermal-time study results. The entire study we provide a guideline for the design of LED high bays in future and demonstrate the importance of the thermal interface materials in the design studied.
{"title":"The Effect of Thermal Interface Material on Led Heat Sinks","authors":"Deepa Chandran","doi":"10.24321/2349.7661.201801","DOIUrl":"https://doi.org/10.24321/2349.7661.201801","url":null,"abstract":"LED’S have been used in many products due to its longevity, more power saving and higher lumens per watt. About 80% of the electrical power is wasted as heat or reductant heat which in turn increases the junction temperature of the LED’s. This increase in the temperature in the LED’S decreases the longevity and color of LED’S. Proper thermal management is required to remove this heat effectively. The heat sink design and usage of proper thermal interface materials for increasing the heat removal is required. In this paper, temperature increase in a LED fixture during a time interval with and without thermal interface material is measured and tabulated to find the effectiveness of the thermal interface material in removing more heat is studied. In addition, a simulation using Solidworks thermal simulation is done to validate the analytical thermal-time study results. The entire study we provide a guideline for the design of LED high bays in future and demonstrate the importance of the thermal interface materials in the design studied.","PeriodicalId":412436,"journal":{"name":"Journal of Advanced Research in Applied Mechanics & Computational Fluid Dynamics","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123392459","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 : 1900-01-01DOI: 10.24321/2349.7661.201802
N. Subaschandar
This paper presents an analysis of fluid flow in a typical manifold. A commerciallyavailable Computational Fluid Dynamics (CFD) package has been used to analyze the flow pattern inside the manifold. Temperatureand velocity in whole fluid domain and mass flow rate in all the outlets in the manifold have been computed. Based on the preliminary results, a simple modification to inside of the main pipe of the manifold has been incorporated. The performance of the modified design has been compared with the original design from the point of view of average temperature and mass flow rate at the outlets. This simple modification has been shown to improve the uniformity of temperature and mass flow at the outlets, thus enhancing the efficiency of the mixing manifold.
{"title":"Flow Mixing Optimisation inside a Manifold using Computational Fluid Dynamics","authors":"N. Subaschandar","doi":"10.24321/2349.7661.201802","DOIUrl":"https://doi.org/10.24321/2349.7661.201802","url":null,"abstract":"This paper presents an analysis of fluid flow in a typical manifold. A commerciallyavailable Computational Fluid Dynamics (CFD) package has been used to analyze the flow pattern inside the manifold. Temperatureand velocity in whole fluid domain and mass flow rate in all the outlets in the manifold have been computed. Based on the preliminary results, a simple modification to inside of the main pipe of the manifold has been incorporated. The performance of the modified design has been compared with the original design from the point of view of average temperature and mass flow rate at the outlets. This simple modification has been shown to improve the uniformity of temperature and mass flow at the outlets, thus enhancing the efficiency of the mixing manifold.","PeriodicalId":412436,"journal":{"name":"Journal of Advanced Research in Applied Mechanics & Computational Fluid Dynamics","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126912961","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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