Sreekant Narumanchi Travels the Intersection of Heat Transfer, Power Electronics, and Electric Motors to Electrification of Vehicles

Sreekant Narumanchi Travels the Intersection of Heat Transfer, Power Electronics, and Electric Motors to Electrification of Vehicles

He Is One of NREL's 2024 Distinguished Members of Research Staff

Sreekant Narumanchi's passion for science got off to a rolling start as a boy.

His dad was a mechanical engineer in Ranchi, and then Hyderabad, India. "I looked up to my father," Narumanchi said. "And I still look up to him."

It is quite a legacy: To this day, the elder Narumanchi, who is 83, goes into his company's office twice a week. His enjoyment of engineering was contagious.

Yet Narumanchi, who now leads the National Renewable Energy Laboratory's (NREL's) Advanced Power Electronics and Electric Machines group, found his own path early on at a specific crossroads of inquiry.

"I was interested in the intersection of physics and mechanical engineering," he said. "The area of heat transfer is like that intersection."

Even as he worked his way through the Indian Institute of Technology as an undergraduate student majoring in mechanical engineering, his eyes were also on another goal: coming to the United States to experience the benefits of higher education and employment here.

"I became interested in research and wanted to go deeper into heat transfer," he said. "I confess to having a fascination with the U.S. higher education system and pursuing a career here. I thought, 'Why don't I take my shot at it?'"

He came to Washington State University as a research assistant because the school offered him a stipend and full tuition for his master's degree.

"It was good, but I wanted to find a top-five school," he said.

Carnegie Mellon University then offered him a stipend for his doctoral study. The focus of most heat transfer research in electronics packaging was in the context of computers and data centers.

"It was about computers and data centers at that point. That was the area for thermal engineers and researchers like me," he said. Electric vehicles (EVs), motors, power electronics, and the like were an afterthought. Even his professors rarely talked about renewable mobility.

"It seemed like an area where not much had been done," Narumanchi said.

However, in 2004, one of his professors did share an advertisement for a postdoctoral position at NREL in a fledgling group focused on transportation. This introduced Narumanchi to another heat transfer intersection: power electronics and thermal management.

The NREL Expressway

While most engineers at the time were not envisioning a future for electric vehicles, Narumanchi said he sensed an opportunity. He eagerly joined the laboratory-not only for the novel challenge but also NREL's purpose.

His timing was good. EVs were revving up.

In general, electrified mobility applications rely on power electronics, such as inverters, converters, and chargers, to manage electricity flow between the battery, electric motor, and other powertrain components. Understanding the connections are crucial.

As EVs and other machines became more advanced, so did their issues. His expertise in heat transfer would soon prove vital. As people were discovering, overheating can cause irreparable damage to power electronics and electric motors. Once that happens, systems can slow or stop functioning altogether.

Drawing upon his passion, he dove in and eventually contributed to various developments, racking up five patents, numerous papers, several collaborations, and an R&D 100 Award along the way. Old ideas gave way to new insights-and continue today.

"We are in the business of design, development, evaluation, commercialization of these next-generation power electronics and electric machine components," he said.

A Vision for the Future

And as in other realms of renewable energy and energy efficiency, there is a sense of urgency. Narumanchi is blunt: "We are trying to understand the failure modes and mechanisms by subjecting these to those accelerated conditions because we don't have the luxury of waiting 15-30 years to find out how these components perform."

Currently, his group of 15 full-time researchers has expanded and diversified its skills. Equally important, for nearly 20 years, his group has collaborated with more than 80 institutions from academia, other laboratories, and industry.

"We're trying to electrify vehicles across a number of applications areas (land, air, marine, rail) to improve their performance, lower costs, increase range, ensure they are reliable, and reduce fuel consumption and greenhouse gas emissions," Narumanchi said. The benefits would be immense.

To further this progress, Narumanchi serves as co-lab lead of the Electric Drive Technologies Program within the U.S. Department of Energy's Vehicle Technologies Office and on the advisory boards for National Science Foundation centers and universities.

Not surprisingly, he was chosen as one of NREL's Distinguished Members of Research Staff in 2024.

There have been other honors, too, for this innovator. Last year, Narumanchi received the Avram Bar-Cohen Memorial Medal from the American Society of Mechanical Engineers. Named posthumously after an engineering pioneer Narumanchi knew, the award is in recognition of his meaningful contributions to the fields of thermal management, power electronics, and electric machines.

When not at NREL, Narumanchi and his wife enjoy taking their two sons to theme parks and going to the movies. He is grateful to be where he is and for where he has come from. Narumanchi said he is "glad that we were able to take our shot" at the field of electric mobility.

As he has since he was a boy, Narumanchi looks forward to more progress.

"I believe that there continue to be significant opportunities in the electrification of medium- and heavy-duty on-road vehicles, vehicles for construction, mining, agriculture, rail, marine, and aircrafts. It seems like a laundry list, but it could have a real impact," he said.

And Narumanchi is happy at NREL.

"NREL's mission has always been extremely noble. It was in 2004," he said. "It seems extremely noble now."