Scope and Objectives

1. design of periodic unit cell foam geometry for acoustic and thermal co-design 2. scale up of the unit-cell to noise attenuating heat-sink structure (build macro-scale foam from the mesoscale unit-cell) 3. fabrication of the periodic foam heat sinks and experimental verification of acoustical and thermal performance 4. proof-of-concept demonstration of heat sinking and noise attenuation performance of the foam in laptop form-factor

Deliverables

1. Proof-of-concept demonstration of noise-reducing-heat-sinks in a laptop form factor 2. Experimentally measured acoustic and thermal properties database of periodic foam materials 3. Acoustic and thermal models for predicting effective properties of periodic foam materials

Scientific Output

1. Developed criteria for evaluating and optimizing noise-reducing heat sinks 2. Periodic foam structures were designed based on Johnson-Champoux-Allard (JCA) model 3. The "Inverse method" to experimentally determine JCA parameters based on impedance tube measurements was implemented. 4. The ultrasonic or direct method to experimentally determine JCA parameters is ongoing. 5. A test setup has been developed to demonstrate noise reducing heat sink prototypes.

Results and outcome till date

Target for this work is to arrive at broadband noise reducing heat sink technology where dual functions noise absorption as well as heat dissipation occur concomitantly within the same functional volume. Such a multifunctional technology does not exist in the open literature. At this stage, we are in a position to showcase an early-stage prototype that validates an analytical framework we developed for achieving near-optimal noise-reducing heat sinks. Steps achieved: 1. Facilities were created 2. Unit cell design models and prototypes were developed (pictures not shown due to confidentiality) and experimental verification/validation of the models were done 3. preliminary proof of concept for thermal acoustic performance of noise reducing heat sinks

Societal benefit and impact anticipated

Next steps

Complete the remaining test set ups to characterize porous materials used in the noise reducing heat sinks Fabricate and experimentally demonstrate new designs for noise reducing heat sinks Proof of concept demonstration in laptop form factor

Publications and reports

Publications: 1. S. Ramamoorthy and S. Krishnan, "Towards thermal-acoustic co-design of noise reducing heat sinks", IEEE transactions on Components, packaging, and manufacturing technology, 8(8), pages 1411-1419, 2018. 2. V. Agarwal and S. Ramamoorthy, "Predicting the acoustical characteristics of reticulated periodic foams", Proceedings of the National Symposium on Acoustics, October 28-30, 2017, AMU-Aligarh, India 3. S. Deshmukh and S. Ramamoorthy, "Dependence of macro-scale response of fibrous materials on polygonal arrangement of fibers", Proceedings of the National Symposium on Acoustics, October 28-30, 2017, AMU-Aligarh, India 4. S. Deshmukh and S. Ramamoorthy, "Design of periodic foam structures based on Johnson-Champoux-Allard model", WESPAC conference, November 2018, New Delhi, India 5. R. H. Bhimrao, S. Krishnan, and S. Ramamoorthy, "Measurement of combined thermal-acoustic performance of noise-reducing heat sinks", WESPAC conference, November 2018, New Delhi, India Reports: 1. Hemdeep Padalia, "Design and implementation of four-microphone acoustic impedance tube to characterize porous materials", Dual degree project, 2017. 2. Vinayak Agarwal, "Determination of Johnson-Champoux-Allard parameters for reticulated porous material using impedance tubes", Dual degree project, 2018.

Patents

Invention disclosure filed; title: noise reducing heat dissipation devices, Nov, 2018

Scholars and Project Staff

PhD Scholars working on this project :
Sagar Deshmukh Ronge Harshavardhan Bhimrao (MHRD scholarship)
Swati Sachan Masters student: Jadhav Aniket Sahebrao

Technical Project staff:
Meghana Maddala Radhika Chowdhury

Non-technical (admin) project staff:
Sudha Vijay Dhanve Graduated Masters students who partly worked on this project, but funded by MHRD schlolarship:
Vinayak Agarwal (Dual B.Tech-M.Tech, 2018)
Hemdeep Padalia (Dual B.Tech-M.Tech, 2017)

Other information

Funding utilization shown is up to July 31, 2018. Purchases in progress are not reflected in these numbers.