Industrial Consultancy & Sponsored Research (IC&SR) , IIT Madras
Rotatable Heat Sink
Technology Category/Market
Category- Electronics & Circuits
Industry Classification:
NIC (2008)- 2610– Manufacture of electronic components
Applications:
Cooling of electronic devices such as mobile phones, reduction of temperature in avionics etc.
Market report:
The global market for heat sinks was estimated at USD 7.37 billion in 2023 and is projected to grow to USD 12.99 Billion by 2032 with a CAGR of 6.50%.
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Problem Statement
- Heat sinks facilitate the heat generating elements on devices to dissipate heat by providing a larger heat transfer area.
- However, these heat sinks were based on sensible heat causing the device temperatures to rise with time.
- Phase Change Material (PCM) based heat sinks address the problem by absorbing latent heat. However, The major design goal in a PCM based heat sink would be to stretch the latent heat time during charging and to reduce the discharging cycle time.
- A novel heat sink technology of air-based impeller type heat sinks have emerged. However, air and PCM based heat sinks have not been subject to rotation.
- There is a need for a simple, effective and efficient heat sink with maximum operation time during heat cycle and minimum operation time during the cooling cycle.
Technology
- The device comprises of heat sink capable of rotating and mounted on a motor, and a phase changing material stored within the heat sink. The sink is adapted to be in relative motion with respect to air to cool the component.
- The sink preferably made of aluminum may be with or without an internal central stem and radial fins . The Phase Changing Material (PCM) is preferably n-eicosane which is filled in the cylinder at a number of ratios and may also be used at different orientations and rotational speeds.
- Experimental investigations of the effect of fins, gravity, rotational convection and mass of the phase change material (PCM) on the thermal performance of a heat sink subjected to constant heat flux of 5 kW/m2 at the base were disclosed.
- The heat sink was subject to four fill ratios (0, 0.33, 0.66,0.99) of PCM/air, nine orientations 25 (0,45,90,135,180,225,270, 315, 360), and three rotational speeds (0,60,120 RPM) simultaneously.
- Regardless of the configuration, rotation has a positive effect of 25 % performance enhancement on melting, only at lower fill ratios. However, rotation was found to have a negligible effect at higher fill ratios.
- A finned heat sink performs the best among the three chosen configurations with an enhancement ratio 10.25, while incurring highest cost.
- There is always a conflict between the cost and the performance for all configurations. This can be resolved by the designer keeping in mind the application and the requirement.
Key Features/Value Proposition
- The performance of PCM based heat sink is superior to air-based heat sink during the heating/melting cycle, and vice versa during the cooling/solidification cycle
- The combined effects of latent and sensible heat is the best for a heat sink cylinder comprising both the PCM as well as fins as it makes use fins to spread the heat from the base uniformly in the PCM.
- In real world applications the orientation of an un-finned heat sink containing a PCM can vary as per operating conditions. The enhancement ratio of the invented heat sink with 99% PCM fill is insensitive to orientation making it reliable from an engineering perspective.
- The invented rotating heat sink addresses the problem of stagnant air near heat sink walls observed in conventional heat sinks.
- The invention allows wide scope of customization based on various factors such as fill ratio, presence of fins and orientation for working out optimum performance and cost trade-offs.
Questions about this Technology?
Contact for Licensing
Research Lab
Prof. Chakravarthy Balaji
Department of Mechanical Engineering
Intellectual Property
- IITM IDF Ref.1282
- IN 352112 Patent Granted
Technology Readiness Level
TRL 3
Experimental Proof of concept