Pub Date : 2020-07-01DOI: 10.1109/ITherm45881.2020.9190299
Justin Wang, M. Fish, M. Berman, Melissa K. McCann
This work presents a two-temperature model (TTM) designed to understand the thermal response of time-scale matched, phase-change PureTemp29-gallium composites. Since explicit, subscale thermal modeling of the aforementioned composites is computationally expensive, a system-level alternative capable of accurately capturing the full range of dynamic responses of PureTemp29 and gallium – the TTM – is discussed. In the TTM, each element is designed to simultaneously track temperatures of gallium and PureTemp29. The derived parameters – K, the coupling coefficient which depends on subscale composite structure and material, and keff, the effective thermal conductivity – are tuned using a fitting algorithm, resulting in the convergence of the TTM’s thermal response to that of the explicit model. The derived parameters are found to be boundary-condition independent, i.e., varying the heat-flux has negligible impact on K and keff. From large-scale parametric sweeps and stepwise regression, two empirical correlations between the derived parameters and four subscale material parameters are developed. These correlations will be refined to develop a full material model for time-scale matched phase-change composites.
{"title":"Towards Time-Scale Matched Composites: System-Level Modeling of Organic and Metallic Phase-Change Material Composites Using a Two-Temperature Model","authors":"Justin Wang, M. Fish, M. Berman, Melissa K. McCann","doi":"10.1109/ITherm45881.2020.9190299","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190299","url":null,"abstract":"This work presents a two-temperature model (TTM) designed to understand the thermal response of time-scale matched, phase-change PureTemp29-gallium composites. Since explicit, subscale thermal modeling of the aforementioned composites is computationally expensive, a system-level alternative capable of accurately capturing the full range of dynamic responses of PureTemp29 and gallium – the TTM – is discussed. In the TTM, each element is designed to simultaneously track temperatures of gallium and PureTemp29. The derived parameters – K, the coupling coefficient which depends on subscale composite structure and material, and keff, the effective thermal conductivity – are tuned using a fitting algorithm, resulting in the convergence of the TTM’s thermal response to that of the explicit model. The derived parameters are found to be boundary-condition independent, i.e., varying the heat-flux has negligible impact on K and keff. From large-scale parametric sweeps and stepwise regression, two empirical correlations between the derived parameters and four subscale material parameters are developed. These correlations will be refined to develop a full material model for time-scale matched phase-change composites.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129824572","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 : 2020-07-01DOI: 10.1109/ITherm45881.2020.9190300
Beichao Hu, Cheng-Xian Lin, D. Patel, Y. Joshi, J. Vangilder, M. Seymour
Cooling air in data center is most commonly supplied by Computer Room Air Handler (CRAH) units through a raised-floor plenum and is eventually delivered through perforated tiles into the computer room. The flow rate distribution on perforated tiles is crucial to the amount of cooling air delivered to rack units in the cold aisle, which dominates the cooling effect of the entire computer room. Among many factors affecting the flow rate distribution, plenum modeling is one of the most important factors. Computational Fluid Dynamics (CFD) tools are usually applied to predict the temperature and velocity profile in data centers. However, most of literatures in the past focused on perforated tile modeling and server modeling in the computer room. Plenum was usually intentionally neglected and flow rate on the perforated tiles were specified as boundary conditions. It was also reported [1] that the prediction of the flow rate distribution was difficult. This paper studies the tile flow rate distribution based on CFD simulation. The CFD result was then compared with the result of an experiment taken in Georgia Tech.
{"title":"A Comprehensive CFD Study of Tile Flow Rate Distribution in a Compact Data Center Laboratory","authors":"Beichao Hu, Cheng-Xian Lin, D. Patel, Y. Joshi, J. Vangilder, M. Seymour","doi":"10.1109/ITherm45881.2020.9190300","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190300","url":null,"abstract":"Cooling air in data center is most commonly supplied by Computer Room Air Handler (CRAH) units through a raised-floor plenum and is eventually delivered through perforated tiles into the computer room. The flow rate distribution on perforated tiles is crucial to the amount of cooling air delivered to rack units in the cold aisle, which dominates the cooling effect of the entire computer room. Among many factors affecting the flow rate distribution, plenum modeling is one of the most important factors. Computational Fluid Dynamics (CFD) tools are usually applied to predict the temperature and velocity profile in data centers. However, most of literatures in the past focused on perforated tile modeling and server modeling in the computer room. Plenum was usually intentionally neglected and flow rate on the perforated tiles were specified as boundary conditions. It was also reported [1] that the prediction of the flow rate distribution was difficult. This paper studies the tile flow rate distribution based on CFD simulation. The CFD result was then compared with the result of an experiment taken in Georgia Tech.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"3999 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127531193","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 : 2020-07-01DOI: 10.1109/ITherm45881.2020.9190430
R. Ghaffarian
Stack electronic packaging technologies have now been widely implemented to increase the capabilities of commercial electronics in order to overcome the limitation of die fabrication with extremely finer features. An special 3D leaded confguration using internally packaged memory has been widely used for high-reliability applications. Its new configuration comes in high-temperature ball grid array (BGA), which may be less robust than the leaded version.This paper compares thermal cycle reliability of 3D stack assemblies with two configurations—leaded and BGA. The two configurations were subjected to either accelerated thermal cycle (ATC) alone or with subsequent extremer thermal shock cycle (ATSC) in two ranges in order to determine robustness and to initiate earlier failures. The ATCs were in the range of – 55°C to 100°C whereas the ATSCs ranged from–100°C to 125°C. Extreme cold temperature exposure to –100°C is representative of mild deep space environment whereas possibly none for industrial applications.Visual inspection with optical microscopy images dcoumented damage progression for leaded 3D assemblies with and without workmanship defects. However, daisy-chain resistance continuity monitoring was used as the key verification method for detecting failure of 3D BGA and using visual inspection as a secondary approach for monitoring damage progression. The inspection results were presented in detail for leaded assemblies with and without the edge adhesive staking. For 3D stack BGA assemblies, results of failure analyses were also presented. These were were performed by cross-sectioning with optical and scanning electron microscopy evaluation.
{"title":"Assembly Reliability of 3D Stacks under Thermal Cycles","authors":"R. Ghaffarian","doi":"10.1109/ITherm45881.2020.9190430","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190430","url":null,"abstract":"Stack electronic packaging technologies have now been widely implemented to increase the capabilities of commercial electronics in order to overcome the limitation of die fabrication with extremely finer features. An special 3D leaded confguration using internally packaged memory has been widely used for high-reliability applications. Its new configuration comes in high-temperature ball grid array (BGA), which may be less robust than the leaded version.This paper compares thermal cycle reliability of 3D stack assemblies with two configurations—leaded and BGA. The two configurations were subjected to either accelerated thermal cycle (ATC) alone or with subsequent extremer thermal shock cycle (ATSC) in two ranges in order to determine robustness and to initiate earlier failures. The ATCs were in the range of – 55°C to 100°C whereas the ATSCs ranged from–100°C to 125°C. Extreme cold temperature exposure to –100°C is representative of mild deep space environment whereas possibly none for industrial applications.Visual inspection with optical microscopy images dcoumented damage progression for leaded 3D assemblies with and without workmanship defects. However, daisy-chain resistance continuity monitoring was used as the key verification method for detecting failure of 3D BGA and using visual inspection as a secondary approach for monitoring damage progression. The inspection results were presented in detail for leaded assemblies with and without the edge adhesive staking. For 3D stack BGA assemblies, results of failure analyses were also presented. These were were performed by cross-sectioning with optical and scanning electron microscopy evaluation.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130547186","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 : 2020-07-01DOI: 10.1109/ITherm45881.2020.9190584
Mohammad I. Tradat, Ghazal Mohsenian, Yaman M. Manaserh, B. Sammakia, Dave Mendo, H. Alissa
Data center cooling energy efficiency is critical to the successful operation of modern large data centers. In 2014, data centers in the U.S. consumed an estimated 70 billion kWh of electricity, representing about 1.8% of total U.S. electricity consumption. Given that the cooling infrastructure can average 40% of the total data center energy consumption, suggests the data center cooling energy consumed in 2014 can be approximated at 28 billion kWh. These numbers indicate that improving airflow management in order to improve the efficiency of cooling in data centers can significantly affect operating costs and allow for increased IT capacity, thereby extending the life of the data center. Some of the methods used to improve airflow include, but are not limited to, hot aisle and cold aisle containment, IT equipment alignment and configuration changes, bypass air management (e.g. cable penetrations), recirculation management (e.g. blanking panels). Other methods that can be deployed to improve cooling energy efficiency include air and/or waterside economization, variable frequency drives (VFD), and increased IT equipment inlet (supply air) temperatures, etc.Most of the above-mentioned thermal management technologies concentrate on managing airflow to achieve the desired server inlet temperature (supply air operating set point) and not to manage the amount of cool air (CFM) that each IT server should receive in order to remove the produced heat. However, airflow is equally important for quantifying adequate cooling to IT equipment, but it is more challenging to measure the airflow per server and hence per rack. Therefore, as a potential option for measuring this airflow an experimental based airflow measurement was performed in this study to quantify and compare between different devices including commercial flow hood, vane anemometer, and Mobile Temperature/Velocity Mesh (MTVM). Furthermore, the effect of measurement location (rack front/rear), type of IT equipment/rack, rack location and depth were investigated. On one hand, the results revealed that the rack airflow rate prediction using average inlet/outlet temperature across the rack was the most accurate and practical technique when compared to airflow reference value which was based on IT equipment pressure-flowrate curve. On the other hand, the measured flow rate using the flow hood at rack inlet face reported a 10% off from the reference value for rack C 1-8. Using flow hood for rack airflow is impractical to be used in real data centers. Therefore and based on the conducted comparison in this study, measuring air temperature across the rack inlet and outlet could be the easiest method to predict the actual rack airflow rate (i.e. supply at rack intake) and hence manage the airflow by compromising the supply to the IT equipment demand based on their flow curves.
{"title":"Experimental Analysis of Different Measurement Techniques of Server-Rack Airflow Predictions Towards Proper DC Airflow Management","authors":"Mohammad I. Tradat, Ghazal Mohsenian, Yaman M. Manaserh, B. Sammakia, Dave Mendo, H. Alissa","doi":"10.1109/ITherm45881.2020.9190584","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190584","url":null,"abstract":"Data center cooling energy efficiency is critical to the successful operation of modern large data centers. In 2014, data centers in the U.S. consumed an estimated 70 billion kWh of electricity, representing about 1.8% of total U.S. electricity consumption. Given that the cooling infrastructure can average 40% of the total data center energy consumption, suggests the data center cooling energy consumed in 2014 can be approximated at 28 billion kWh. These numbers indicate that improving airflow management in order to improve the efficiency of cooling in data centers can significantly affect operating costs and allow for increased IT capacity, thereby extending the life of the data center. Some of the methods used to improve airflow include, but are not limited to, hot aisle and cold aisle containment, IT equipment alignment and configuration changes, bypass air management (e.g. cable penetrations), recirculation management (e.g. blanking panels). Other methods that can be deployed to improve cooling energy efficiency include air and/or waterside economization, variable frequency drives (VFD), and increased IT equipment inlet (supply air) temperatures, etc.Most of the above-mentioned thermal management technologies concentrate on managing airflow to achieve the desired server inlet temperature (supply air operating set point) and not to manage the amount of cool air (CFM) that each IT server should receive in order to remove the produced heat. However, airflow is equally important for quantifying adequate cooling to IT equipment, but it is more challenging to measure the airflow per server and hence per rack. Therefore, as a potential option for measuring this airflow an experimental based airflow measurement was performed in this study to quantify and compare between different devices including commercial flow hood, vane anemometer, and Mobile Temperature/Velocity Mesh (MTVM). Furthermore, the effect of measurement location (rack front/rear), type of IT equipment/rack, rack location and depth were investigated. On one hand, the results revealed that the rack airflow rate prediction using average inlet/outlet temperature across the rack was the most accurate and practical technique when compared to airflow reference value which was based on IT equipment pressure-flowrate curve. On the other hand, the measured flow rate using the flow hood at rack inlet face reported a 10% off from the reference value for rack C 1-8. Using flow hood for rack airflow is impractical to be used in real data centers. Therefore and based on the conducted comparison in this study, measuring air temperature across the rack inlet and outlet could be the easiest method to predict the actual rack airflow rate (i.e. supply at rack intake) and hence manage the airflow by compromising the supply to the IT equipment demand based on their flow curves.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"312 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132863500","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 : 2020-07-01DOI: 10.1109/ITherm45881.2020.9190562
Amitav Tikadar, Nitish Kumar, Y. Joshi, Satish Kumar
Permanent magnet synchronous motors (PMSM) are extensively used in electric vehicles. However, high internal heat generation and inefficient heat dissipation often limit the operational reliability, and longevity of the PMSM. Therefore, proper quantification of heat generation in electric motor and advanced embedded motor cooling techniques remain topics of immense interest. In order to accurately predict electro-magnetic performance, i.e., efficiency, component-wise heat losses and the corresponding temperature distribution of a jacket cooled machine, this paper presents a two-way iteratively coupled electro-thermal modeling framework. Finite element based software Motor-CAD has been utilized for electrom-agnetic performance calculation of BMW i3 PMSM. Finite volume based computational fluid dynamics/heat transfer (CFD/HT) software ANSYS® FLUENT® has been employed to simulate the temperature distribution of the PMSM, using the electro-magnetic losses as heat input. Computed heat losses, stator, winding, rotor, and magnet temperatures are utilized as coupling parameters between the electro-magnetic and thermal models. A conventional one-way coupling algorithm has also been developed and compared to the newly proposed two-way coupling algorithm. Numerical results confirm that at high current density, one-way coupling algorithm significantly over-predicts the motor temperature compared to the two-way algorithm. A comprehensive analysis has been carried out to characterize the influences of current density, speed, and forced convection heat transfer coefficient on the heat losses, overall efficiency, and maximum temperature of the PMSM. Finally, an efficiency map has been interpreted from the coupled electro-magnetic simulation.
{"title":"Coupled Electro-Thermal Analysis of Permanent Magnet Synchronous Motor for Electric Vehicles","authors":"Amitav Tikadar, Nitish Kumar, Y. Joshi, Satish Kumar","doi":"10.1109/ITherm45881.2020.9190562","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190562","url":null,"abstract":"Permanent magnet synchronous motors (PMSM) are extensively used in electric vehicles. However, high internal heat generation and inefficient heat dissipation often limit the operational reliability, and longevity of the PMSM. Therefore, proper quantification of heat generation in electric motor and advanced embedded motor cooling techniques remain topics of immense interest. In order to accurately predict electro-magnetic performance, i.e., efficiency, component-wise heat losses and the corresponding temperature distribution of a jacket cooled machine, this paper presents a two-way iteratively coupled electro-thermal modeling framework. Finite element based software Motor-CAD has been utilized for electrom-agnetic performance calculation of BMW i3 PMSM. Finite volume based computational fluid dynamics/heat transfer (CFD/HT) software ANSYS® FLUENT® has been employed to simulate the temperature distribution of the PMSM, using the electro-magnetic losses as heat input. Computed heat losses, stator, winding, rotor, and magnet temperatures are utilized as coupling parameters between the electro-magnetic and thermal models. A conventional one-way coupling algorithm has also been developed and compared to the newly proposed two-way coupling algorithm. Numerical results confirm that at high current density, one-way coupling algorithm significantly over-predicts the motor temperature compared to the two-way algorithm. A comprehensive analysis has been carried out to characterize the influences of current density, speed, and forced convection heat transfer coefficient on the heat losses, overall efficiency, and maximum temperature of the PMSM. Finally, an efficiency map has been interpreted from the coupled electro-magnetic simulation.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127837473","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 : 2020-07-01DOI: 10.1109/ITherm45881.2020.9190356
R. V. Erp, G. Kampitsis, L. Nela, R. Ardebili, E. Matioli
In this work, we demonstrate a new thermal management approach for direct cooling of GaN-on-Si power integrated circuits (ICs), in which the Si substrate functions as a microfluidic heat sink, turning Si into a cost-effective, high thermal performance substrate. Flowing coolant through microchannels etched in the backside of the substrate enables a much denser integration of GaN power devices in a single chip. As a proof of concept, an integrated full-wave bridge rectifier (FWBR) was realized based on high-performance tri-anode GaN Schottky barrier diodes (SBDs), together with a novel hybrid printed circuit board (PCB) that provides fluidic and electric connections to the liquid-cooled power IC. A device-level heat flux of 417 W/cm2 was cooled using only 60 mW of pumping power. Compared to natural-convection air-cooling, the temperature rise was reduced by 98% and the converter output power was increased by 30 times, up to 120 W, by eliminating self-heating degradation. The high cooling efficiency, large heat extraction capabilities and low-cost fabrication process of embedded microchannels on GaN-on-Si, in combination with new PCB-based coolant delivery, can be an enabling technology for the next generation of ultra-high power-density ICs.
{"title":"Embedded Microchannel Cooling for High Power-Density GaN-on-Si Power Integrated Circuits","authors":"R. V. Erp, G. Kampitsis, L. Nela, R. Ardebili, E. Matioli","doi":"10.1109/ITherm45881.2020.9190356","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190356","url":null,"abstract":"In this work, we demonstrate a new thermal management approach for direct cooling of GaN-on-Si power integrated circuits (ICs), in which the Si substrate functions as a microfluidic heat sink, turning Si into a cost-effective, high thermal performance substrate. Flowing coolant through microchannels etched in the backside of the substrate enables a much denser integration of GaN power devices in a single chip. As a proof of concept, an integrated full-wave bridge rectifier (FWBR) was realized based on high-performance tri-anode GaN Schottky barrier diodes (SBDs), together with a novel hybrid printed circuit board (PCB) that provides fluidic and electric connections to the liquid-cooled power IC. A device-level heat flux of 417 W/cm2 was cooled using only 60 mW of pumping power. Compared to natural-convection air-cooling, the temperature rise was reduced by 98% and the converter output power was increased by 30 times, up to 120 W, by eliminating self-heating degradation. The high cooling efficiency, large heat extraction capabilities and low-cost fabrication process of embedded microchannels on GaN-on-Si, in combination with new PCB-based coolant delivery, can be an enabling technology for the next generation of ultra-high power-density ICs.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123335542","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 : 2020-07-01DOI: 10.1109/ITherm45881.2020.9190302
Joe Alexandersen
This paper applies a previously developed framework for topology optimisation of passive cooling to a vertically-oriented electronics cabinet with multiple heat generating chips. The flow field in the cabinet is complex due to the buoyancy generated by the multiple chips interacting with each other. Thus, it becomes difficult to intuitively design heat sinks for this application. Therefore, topology optimisation is applied to generate optimised heat sink geometries customised for the actual layout of chips inside the cabinet. Both a full Navier-Stokes flow model and an approximate flow model is applied to the problem. The approximate model is shown to be insufficient on its own for the defined problem and the full model is shown to be computationally expensive and unstable. A hybrid optimisation approach is then applied, using the full model in the beginning to point the optimisation in the right direction and the approximate model in the subsequent stages to fine tune the heat sink designs. The full model is shown to introduce flow-aware features in the heat sink designs, that increase the performance substantially. It is concluded that heat sink designs should be different for each of the chips in the cabinet depending on its location and interaction with the thermal plumes from other chips.
{"title":"Application of Full and Approximate Flow Models in Topology Optimisation of Passive Cooling for Electronics Cabinets","authors":"Joe Alexandersen","doi":"10.1109/ITherm45881.2020.9190302","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190302","url":null,"abstract":"This paper applies a previously developed framework for topology optimisation of passive cooling to a vertically-oriented electronics cabinet with multiple heat generating chips. The flow field in the cabinet is complex due to the buoyancy generated by the multiple chips interacting with each other. Thus, it becomes difficult to intuitively design heat sinks for this application. Therefore, topology optimisation is applied to generate optimised heat sink geometries customised for the actual layout of chips inside the cabinet. Both a full Navier-Stokes flow model and an approximate flow model is applied to the problem. The approximate model is shown to be insufficient on its own for the defined problem and the full model is shown to be computationally expensive and unstable. A hybrid optimisation approach is then applied, using the full model in the beginning to point the optimisation in the right direction and the approximate model in the subsequent stages to fine tune the heat sink designs. The full model is shown to introduce flow-aware features in the heat sink designs, that increase the performance substantially. It is concluded that heat sink designs should be different for each of the chips in the cabinet depending on its location and interaction with the thermal plumes from other chips.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123335678","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 : 2020-07-01DOI: 10.1109/ITherm45881.2020.9190448
Bicheng Chen, Carsten Wulff, Konstantin Etzold, Patrick Manns, Georg Birmes, J. Andert, S. Pischinger
Monitoring critical temperatures in the electric drivetrain components is becoming more and more crucial for operational safety and achieving better efficiency. Instead of a distributed thermal model for each component, in this contribution a centralized compact lumped-parameter thermal network model for the electric drivetrain is set up, so that the thermal coupling between inverter, electric motor and gearbox can be considered. The measured and calibrated loss maps as well as empirical functions for losses distribution in the permanent magnet synchronous machine are used to calculate the losses of components. In the thermal modeling, a-priori system knowledge is taken into account in order to reduce parameter identification effort. A global linear parameter-varying identification approach is applied to find the parameters of the lumped-parameter thermal network model. The parametrized thermal model is cross-validated by independent experimental data on the chassis dynamometer. The maximum estimation error of circa 7 °C is achieved at the ambient temperature around 20 °C with the realistic coolant profiles for automotive scenario. The simulation results demonstrate how good the temperatures can be estimated by a centralized lumped-parameter thermal network regarding the thermal coupling between the components.
{"title":"A Comprehensive Thermal Model For System-Level Electric Drivetrain Simulation With Respect To Heat Exchange Between Components","authors":"Bicheng Chen, Carsten Wulff, Konstantin Etzold, Patrick Manns, Georg Birmes, J. Andert, S. Pischinger","doi":"10.1109/ITherm45881.2020.9190448","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190448","url":null,"abstract":"Monitoring critical temperatures in the electric drivetrain components is becoming more and more crucial for operational safety and achieving better efficiency. Instead of a distributed thermal model for each component, in this contribution a centralized compact lumped-parameter thermal network model for the electric drivetrain is set up, so that the thermal coupling between inverter, electric motor and gearbox can be considered. The measured and calibrated loss maps as well as empirical functions for losses distribution in the permanent magnet synchronous machine are used to calculate the losses of components. In the thermal modeling, a-priori system knowledge is taken into account in order to reduce parameter identification effort. A global linear parameter-varying identification approach is applied to find the parameters of the lumped-parameter thermal network model. The parametrized thermal model is cross-validated by independent experimental data on the chassis dynamometer. The maximum estimation error of circa 7 °C is achieved at the ambient temperature around 20 °C with the realistic coolant profiles for automotive scenario. The simulation results demonstrate how good the temperatures can be estimated by a centralized lumped-parameter thermal network regarding the thermal coupling between the components.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126369563","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 : 2020-07-01DOI: 10.1109/ITherm45881.2020.9190539
A. Vargas, D. Huitink, A. Iradukunda, C. Eddy
Additive manufacturing and topology optimization algorithms have provided a springboard for heat sink development in novel cooling schemes. Here, phase change material (PCM) integrated heat sinks have been constructed using direct metal laser sintering (DMLS) of AlSi10Mg alloy in a two-tier design, incorporating topology optimized fin structures for conducting heat both to the PCM within the tier, as well as to the 2nd tier, where forced air cooling removes energy from the structure. As such, energy removal balancing can be achieved for ameliorating transient power spikes in an electronic package, while maintaining a lower fan power in the air channel. To validate this thermal performance, an experimental testbed was constructed to evaluate these multimode cooling heat sinks, under various heat dissipation and fan power conditions. Sugar alcohol PCMs are evaluated in this effort for passively absorbing a portion of the total heat load in an electronic package heater analog.
{"title":"Topology Optimized Phase Change Material Integrated Heat sinks and Validation","authors":"A. Vargas, D. Huitink, A. Iradukunda, C. Eddy","doi":"10.1109/ITherm45881.2020.9190539","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190539","url":null,"abstract":"Additive manufacturing and topology optimization algorithms have provided a springboard for heat sink development in novel cooling schemes. Here, phase change material (PCM) integrated heat sinks have been constructed using direct metal laser sintering (DMLS) of AlSi10Mg alloy in a two-tier design, incorporating topology optimized fin structures for conducting heat both to the PCM within the tier, as well as to the 2nd tier, where forced air cooling removes energy from the structure. As such, energy removal balancing can be achieved for ameliorating transient power spikes in an electronic package, while maintaining a lower fan power in the air channel. To validate this thermal performance, an experimental testbed was constructed to evaluate these multimode cooling heat sinks, under various heat dissipation and fan power conditions. Sugar alcohol PCMs are evaluated in this effort for passively absorbing a portion of the total heat load in an electronic package heater analog.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126396291","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 : 2020-07-01DOI: 10.1109/ITherm45881.2020.9190425
Ryotaro Yoshikawa, T. Shibuya, Sho Teradaira, Qiang Yu
The purpose of this paper is to analyze the switching behavior with variations in element characteristics using FEM model of power module with multiple elements, investigate the load on each element and the resulting energy loss, and evaluate the cause. The authors performed circuit simulation based on the actual model and calculated the switching loss from the result. Based on this, they examined the analysis conditions in electro-thermal kneading analysis and conducted FEM analysis.
{"title":"Evaluation of Switching Loss and Imbalance in Multi-Element Power Modules","authors":"Ryotaro Yoshikawa, T. Shibuya, Sho Teradaira, Qiang Yu","doi":"10.1109/ITherm45881.2020.9190425","DOIUrl":"https://doi.org/10.1109/ITherm45881.2020.9190425","url":null,"abstract":"The purpose of this paper is to analyze the switching behavior with variations in element characteristics using FEM model of power module with multiple elements, investigate the load on each element and the resulting energy loss, and evaluate the cause. The authors performed circuit simulation based on the actual model and calculated the switching loss from the result. Based on this, they examined the analysis conditions in electro-thermal kneading analysis and conducted FEM analysis.","PeriodicalId":193052,"journal":{"name":"2020 19th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121595655","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：