Education

• Ph.D., University of Pennsylvania, 1984
• M.S., State University of New York, Buffalo, 1981
• B. Tech., Indian Institute of Technology, Kanpur, 1979

Background

Prior to joining the Georgia Tech faculty in 2001 as a Professor, Dr. Joshi held academic positions at the University of Maryland, College Park, and the Naval Postgraduate School, Monterey, California. He also worked in the semiconductor assembly industry on process thermal model development. He was named to the McKenney/Shiver Chair in 2004.

Research

• Heat Transfer, Combustion, and Energy Systems and Micro and Nano Engineering; Thermofluid issues in emerging technologies and microthermal systems

Velocity field and temperature rise above a computer room air conditioning
unit exhaust in a raised floor data center facility, operating at a 100 W/ft^2 power density.

Dr. Joshi's research deals with transport processes associated with emerging technologies in general. Past focus has been on electronic devices, packages and systems. Thermo/fluid challenges arise in these due to strongly localized heating, a wide range of length scales, a multitude of materials and interfaces, and multiple-coupled transport modes. Advances in these areas require an inter-disciplinary approach involving thermal sciences, materials science, semiconductor devices and manufacturing.

Compact Thermal Management Devices: Electronic systems continue to shrink in size with ever increasing functionality. These trends are resulting in heat fluxes at the chip level of over 100 W/cm² in some applications. With an upper limit of 70-125°C as the maximum allowable chip temperature in many applications, acceptable thermal management is a key enabler for next generation electronic systems. A number of liquid and air cooling schemes are being investigated. For example, microfabrication techniques are being employed to develop compact two-phase thermosyphons, single phase heat exchangers and thin heat spreaders. A complementary activity is the modeling of these micro-thermal systems.

Conjugate Transport Mechanisms in Multi-Scale Systems: Rapidly shrinking product development times are demanding high fidelity computational tools for thermal design of electronic systems. Dr. Joshi and students have developed experimentally validated modeling methodologies to analyze multi-mode transport in discretely heated systems with multiple length scales.

Energy Efficient Thermal Management of Facilities: Data center facilities face significant thermal challenges due to increasing cabinet heat loads. Energy efficient thermal management approaches and rapid simulation methodologies for their assessment are under development.

Thermal management continues to be identified by the Semiconductor Industries Association Roadmap as one of the five key challenges during the next decade for achieving the projected performance goals of the industry. Our interests will focus broadly over thermal phenomena associated with electronic systems lifecycle. Development of micro-thermo/fluidic systems as well as data center thermal management will be pursued.

Useful aspects of this research include a combination of experimental and computational approaches to handle problems of contemporary interest, and the development of multidisciplinary expertise encompassing transport phenomena, semiconductor devices, and materials.