Karen Thole

Karen Thole, a Penn State professor and department head of mechanical engineering, strives to improve efficiency in infrastructure.

Look up at the sky right now. Chances are, you might see an airplane somewhere a Penn State faculty member had a hand in designing.

Karen Thole, distinguished professor and department head of mechanical engineering, is a leading researcher in gas turbine efficiency.

Right now, Thole leads a research lab of about 12 graduate students and four full-time staff members who study turbine heat transfer.

“We’re looking at all kinds of ways to make sure that gas turbines are more efficient,” Thole said, “so they take less fuel and have less carbon dioxide emissions.”

According to Thole, turbines power all aircrafts — including commercial flights and military flights. Another function of gas turbines is the ability to generate electricity.

“We have land-based turbines, and about 40% of our electricity right now is generated by natural gas in gas turbines,” Thole said. “As a matter of fact, the Penn State power plant has two gas turbines that produce all the power for Penn State.”

There are three parts to a gas turbine: a compressor to compress the flow of energy, a combustor that burns fuel to raise the temperature of the flow, and the turbine, which extracts its power from the flow.

Thole said the goal of the turbine is to have a high temperature entering it to create maximum efficiency.

However, the temperature of the hot gas can be “maybe 1000s of degrees hotter than the melting temperatures” of the parts involved in the turbine, according to Thole.

What Thole works on is finding ways to cool the turbine so the parts don’t melt. One way she said this can be done is by taking air from the compressor and bypassing the combustor. From there, the air is passed through the turbine, cooling it down.

Thole said she has her own patents on “cooling strategies” used in turbines, which “are now on some engines flying through the sky.”

Hard work has always been a part of Thole’s ethos, and her peers respect her work ethic. Atul Kohli, senior technical at Pratt & Whitney, said he met Thole in 1989 — they met at The University of Texas at Austin while working in the same research group.

Kohli said it’s “amazing to see her story” when thinking of her accomplishments.

“Karen is easily the most hardworking person I have ever known,” Kohli said. “That is why she is where she is.”

Growing up in a small farming community of 49 people — ironically named “Tholeville” — Thole spent her youth in southern Illinois. She was raised on a dairy farm and said her childhood was full of hard work.

By the time she was in fifth grade, Thole was on a tractor driving around the field by her house. When she started college, she didn’t know anything about engineering.


Studying for her undergraduate degree at the University of Illinois at Urbana-Champaign, Thole said one of her friends told her she should try engineering one day after a chemistry class.

“I went home at Christmas break, and I called McDonnell Douglas [now Boeing] — which was in St. Louis, which is about 40 miles from where I live — called the operator and asked if I could talk to their engineer,” Thole said. “I thought they must have one engineer there, and she laughed and said, ‘We have many engineers.”’

From there, Thole said she was introduced to one of the company’s engineers and after a description of his day, she decided, “OK, I’m gonna be an engineer.”

Thole said her love for aircraft came at a young age when her father used to take her to the airport to watch planes take off and land.

Her journey to becoming the Penn State mechanical engineering department head took her all over the country and the world.

Thole finished her bachelor’s and master’s degrees at the University of Illinois at Urbana-Champaign, and after working for a few years in a national lab in California, she decided to get her doctorate at the University of Texas at Austin.

After finishing her doctorate, Thole said she completed post-doctoral work in Germany. From there, she became faculty at the University of Wisconsin-Madison and later at Virginia Polytechnic Institute and State University.

After her time at Virginia Tech, Thole found her way to Penn State and continued her research on gas turbines as a faculty member and department head.

Thole’s expertise on turbines landed her a spot testifying before one of the nation’s highest offices — Congress.

Thole testified before the United States House of Representatives’ Committee on Science, Space & Technology subcommittee on Space and Aeronautics on March 24. The hearing was dedicated to finding forms of “sustainable aviation,” according to Thole.

Because of her 2016 report –– where she and a committee of fellow engineers found ways to reduce carbon dioxide emissions from turbines –– Thole was called in as an expert to detail the findings of this report and give her own say on the matter.

Patricia Stevens, who works for Boeing and leads systems engineering for the cargo and utility helicopters programs, said she thought Thole testifying before Congress was “outstanding.”


Stevens said she and Thole have become “close professional colleagues,” and with her experience, Thole makes a great candidate to present before Congress.

“With that combination of academic leadership in the department, as well as staying very current and prolific [in] her research, it made her a very qualified candidate to make a position before Congress,” Stevens said.

But the winds of time altered Thole’s career course: Thole will step down as the department head of mechanical engineering in August to pursue full-time research.

She will lead a research project funded by NASA, working in collaboration with other universities along with Pratt & Whitney.

Thole’s time as the department head of mechanical engineering increased representation for women in the field.

“We increased the diversity of our faculty,” Thole said. “We now have 29% of our professors [who] are women, [and] we have four other underrepresented groups who became professors in our department.”

Among her peers, Thole is also viewed as a “superb role model” for women in engineering, according to Kohli.

Kohli said Thole is “passionate” about changing the dynamic for women in engineering.

“She’s really a role model for what women in engineering can achieve,” Kohli said.

Thole said she is excited about her future in research, but is also sad to leave the position.

“We accomplished a lot, so I am very sad to step down as the department head,” Thole said. “But, now it’s somebody else’s opportunity to take it to the next level.”

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