Category Archives: Case Study

Posts related to case studies

Case Study: Designing Air-to-Air Heat Exchanger With Heat Pipes

Advanced Thermal Solutions, Inc. (ATS) engineers were tasked by a client to design an air-to-air, aluminum heat exchanger with multiple copper heat pipes that could meet high power demands (more than 400W) with a thermal resistance requirement of 0.046°C/W and could withstand a wide range of ambient temperatures from -40°C to 60°C. Also, the separation between the heat pipe’s evaporator and condenser sections needed to be air tight.

Heat Exchanger

ATS engineers were tasked with designing an air-to-air heat exchanger with heat pipes that would fit inside an enclosure. (Advanced Thermal Solutions, Inc.)

Using analytical modeling, ATS engineers calculated the system pressure drop from the heat pipe to the fin block to the flow turn and also the thermal performance of the fins in ducted flow to determine the proper amount of fins to avoid over pressurizing the fans, while at the same time meeting the thermal resistance demands of the system. It was calculated that a maximum of 14 fins per inch could be used, while the overall size was well within the client’s requirements.

Challenge: To design an air-to-air heat exchanger that could handle high power demands of more than 400W and specific requirements on thermal resistance (0.046°C/W).

Chips/Components: Electronics junction box that requires internal air cooling.

Analysis: ATS engineers conducted analysis of the pressure drop across the system from the heat pipe to the fin block to the flow turn section, as well as analyzing the thermal performance of the entire heat exchanger. This analysis included calculating the ducted flow, heat transfer coefficient, and the fin and heat pipe resistance of the exchanger. The analysis also explored the difference between designs with copper and with aluminum fins.

Design Data: The data showed that thermal resistance and pressure drop of the CFD model were within 16% of the analytical model. The thermal performance of the heat exchanger with heat pipes was 0.044°C/W, meeting the client’s requirements.

Solution: The ATS design was optimized for four heat pipes and a suggestion was made to enhance the heat exchanger by using copper fins, rather than aluminum, because of a higher fin efficiency and lower thermal resistance.

Net Result: The customer was supplied with a production design of a heat exchanger block with heat pipes that could fit into the enclosure and provide the necessary forced convection cooling to maintain the proper temperature for the system. ATS also supplied the heat exchangers from the prototype stage to production.

For more information about Advanced Thermal Solutions, Inc. thermal management consulting and design services, visit www.qats.com or contact ATS at 781.769.2800 or ats-hq@qats.com.

Case Study: Thermal Comparison of Copper and Aluminum Heat Sinks

Advanced Thermal Solutions, Inc. (ATS) engineers were tasked by a client to find a more cost-effective and lighter solution for a custom-designed copper heat sink that dissipated heat from four components on a PCB. ATS engineers compared the thermal performance of the copper heat sink to custom aluminum heat sinks embedded with heat pipes.

Aluminum Heat Sinks

ATS engineers worked on a comparison of a copper heat sink with an aluminum heat sink that had embedded heat pipes running underneath the components. Analysis showed that the aluminum heat sink nearly matched the thermal performance of the copper and was within the margin required by the client. (Advanced Thermal Solutions, Inc.)

Using analytical modeling and CFD simulations, the ATS engineers determined that switching to an aluminum heat sink with heat pipes that run underneath the components yielded case temperatures that were greater than 4.35%, on average, of those achieved with the copper heat sink. The largest difference between the two heat sinks was 9.2°C, over a single component.

Challenge: The client wanted a redesign of a custom copper heat sink to an equivalent or better aluminum heat sink with embedded copper heat pipes.

Chips/Components: Two Inphi (formerly ClariPhy) Lightspeed-II CL20010 DSPs at 96 watts and two Xilinx 100G Gearboxes at 40 watts each.

Analysis: Analytical modeling and CFD simulations determined the junction temperatures between the four components when covered by a copper heat sink (Design 1), by an aluminum heat sink with heat pipes that stop in front of the components (Design 2), and by an aluminum heat sink with heat pipes that run underneath the components (Design 3). The analysis demonstrated the difference between the heat sink designs in relation to thermal performance.

Test Data: CFD analysis showed an average component case temperature of 158.8°C with the original copper heat sink design, 158.3°C with Design 2, and 152°C with Design 3. The average difference in temperature between Design 1 and Design 2 was 0.5°C and the average temperature difference between Design 1 and Design 3 was 6.8°C.

Here is a CFD simulation from the top of the aluminum heat sink with the air hidden, showing the temperature gradient through the heat sink. (Advanced Thermal Solutions, Inc.)

Solution: The client was shown that aluminum heat sinks with heat pipes provided nearly the same thermal performance as the original copper heat sink design and at much lower cost and weight. The component junction temperature differences between Design 1 and Design 3 were well within the margin set by the client.

o The simulated air velocity is lower and the airflow cross section is larger than in the actual application, meaning absolute temperatures are higher than the customer has seen in their testing.

Net Result: Despite using conservative thermal conductivity calculations, aluminum heat sinks with heat pipes were shown to be a more cost-effective solution for achieving the client’s thermal needs than copper.

CLICK HERE FOR A TECHNICAL DISCUSSION OF THIS PROJECT.

For more information about Advanced Thermal Solutions, Inc. thermal management consulting and design services, visit www.qats.com or contact ATS at 781.769.2800 or ats-hq@qats.com.

Case Study: PCB Cooling for Telecom Application

PCB Cooling for Telecom

The layout of the PCB with the smaller but most power-dissipating component on the left and the larger, but less power-dissipating component on the right. Originally both components were covered by straight-fin heat sinks embedded with heat pipes. (Advanced Thermal Solutions, Inc.)


Engineers at Advanced Thermal Solutions, Inc. (ATS) were brought into a project to assist a client with cooling a PCB that was going to be installed in telecommunications data center. The board currently had heat sinks embedded with heat pipes covering the two hottest components but the client wanted a more reliable and cost-effective solution.

ATS engineers used the company’s patented maxiFLOW™ heat sinks to replace the heat pipes and through analytical and CFD modeling determined that by switching to maxiFLOW™ the junction temperature and case temperature would be below the maximum allowed.

Challenge: The client had a new PCB over which air could flow from either direction and two of the highest power dissipating components were on opposite sides.

Chips/Components: WinPath 3 and Vector Processor

Analysis: Analytical modeling and CFD simulations determined the junction temperature with air going from left-to-right and right-to-left and ensured it would be lower than the maximum allowable (100°C for one component and 105°C for the other).

Test Data: With air flowing from left-to-right, CFD simulation determined that the junction temperatures would be 89.3°C and 101.4°C – below the maximum temperatures of 100°C and 105°C. With air flowing from right-to-left, the junction temperature of the most power-dissipating component was 100°C, which was right at the maximum, and the second was at 87°C, which was below it.

Solution: The original heat sinks embedded with heat pipes were switched for maxiFLOW™ heat sinks, with their placement offset slightly to create a linear airflow, and the same levels of thermal performance were achieved.

PCB Cooling for Telecom

ATS engineers changed the embedded heat sinks for maxiFLOW™ heat sinks and received the same thermal performance with a more reliable and cost-effective solution. (Advanced Thermal Solutions, Inc.)

Net Result: The client received the required level of cooling in the PCB, regardless of the direction of air flow, and with a more reliable and cost-effective solution than had been previously been in use.

For more information about Advanced Thermal Solutions, Inc. thermal management consulting and design services, visit www.qats.com or contact ATS at 781.769.2800 or ats-hq@qats.com.

Case Study: High-Powered Altera Stratix 10 FPGAs

Altera Stratix 10 FPGAs`

Advanced Thermal Solutions, Inc. engineers designed a solution to cool a board that contained high-powered Altera Stratix 10 FPGAs. (Advanced Thermal Solutions, Inc.)


Engineers at Advanced Thermal Solutions, Inc. were asked to test the layout of a PCB that was using Altera Stratix 10 FPGAs (field-programmable gate arrays) with fans on one side pulling air across the board. The client used ATS heat sinks on the original iteration of the PCB and wanted to ensure those heat sinks would provide the necessary cooling for this iteration as well.

Through a combination of analytical modeling and CFD simulations, ATS engineers determined that the heat sinks already being used would provide enough cooling for the more powerful components.

Challenge: ATS conducted thermal analysis of a system with Altera Stratix 10 FPGA units when using ATS 1634-C2-R1 and ATS FPX06006025-C1-R0 heat sinks. Two of the FPGAs would be running at 90 watts and one at 40 watts and there were fans on one side of the PCB that would pull air across the board.

Chip/Component: Altera Stratix 10 FPGAs

Analysis: Analytical models and CFD simulations were run with ATS 1634-C2-R1 heat sinks and several other options, including copper and aluminum heat sinks with and without embedded heat pipes. CFD simulations also created fan curves for all six of the Mechtronics MD4028V fans being used.

Test Data: The data showed that even with the additional power of the new chips that the original heat sinks would keep the case temperature below 80°C. The other heat sinks showed similar case temperatures mostly below 80°C as well. Fan curves showed that the fans were operating near the knee, which the client was notified about.

Solution: ATS engineers recommended staying with the ATS 1634-C2-R1 heat sink because it was able to cool the high-powered FPGAs below the maximum case temperature. The ATS FPX06006025-C1-R0 was recommended for the lower power FPGA.

Altera Stratix 10 FPGAs

CFD simulation with the case temperatures of the three FPGA using the original ATS heat sinks.
(Advanced Thermal Solutions, Inc.)

Net Result: The customer was able to continue using the same heat sinks that had worked on the prior iteration of the PCB.

For more information about Advanced Thermal Solutions, Inc. thermal management consulting and design services, visit www.qats.com or contact ATS at 781.769.2800 or ats-hq@qats.com.

Case Study: LED Solution for Outdoor Canopy Array

Advanced Thermal Solutions, Inc. (ATS) was approached by a company interested in a new design for an outdoor LED unit that would be installed in gas station canopies. The original unit was bolted together and contained a molded plastic shroud that held the LED array, the PCB, and an extruded aluminum heat sink.

ATS engineers designed an aesthetically pleasing alternative that utilized natural convection cooling, while increasing the number of the LEDs in the array and its power. The engineers met the customer’s budget and thermal performance requirements.

Challenge: Create an outdoor canopy device that would increase the number of LED in the array, increase power to maximum of 120 watts, and increase lumens, while cooling the device through natural convection.

Chip/Component: The device had to hold an LED array and the PCB that powered it.

Analysis: Analytical modeling and CFD simulations determined the optimal fin efficiency to allow air through the device and across the heat sink, the spreading resistance. The weight of the device was also considered, as it would be outside above customers.

Solution: An aesthetically-pleasing, one-piece, casted unit with built-in electronics box for LED array and PCB was created. There was one inch of headroom between the heat sink and the canopy to allow for heat dissipation and the casting would allow heat transfer as well as allow air to flow through the system.

Net Result: The customer was able to add LEDs to the array and increase power. The new unit also simplified the manufacturing process and cut manufacturing costs.

For more information about Advanced Thermal Solutions, Inc. thermal management consulting and design services, visit www.qats.com or contact ATS at 781.769.2800 or ats-hq@qats.com.