Brendan O'Shaughnessy | November 25, 2017
When air speeds inside a hypersonic wind tunnel are expected to reach 4,000 miles per hour, the crafting of the most critical part of the tunnel — its 25-foot, 5-ton stainless steel nozzle – needs to be hyper-exact.
So the aerospace engineers designing Notre Dame’s Mach 6 wind tunnel turned to their in-house experts at the machine shop in the basement of the Hessert Laboratory for Aerospace Research.
“There need to be 21 pieces that can fasten together because each piece needs to be hand polished to perfection to minimize friction,” said Gene Heyse, manager of the machine shop in the aerospace and mechanical engineering department. “It needs a 7 percent taper on the inside, and it has to be perfect to 1/10 of a thousandth of an inch. So we built our own gauge to measure it accurately.”
A tenth of a thousandth of an inch is 40 times smaller than the width of a human hair.
That kind of problem-solving and that level of precision are why professors and researchers across campus and beyond turn to the Hessert machine shop to build the devices they need for cutting-edge research.
As a Notre Dame core facility, the shop charges $59 per hour, less than outside companies that may charge $85 to $200 an hour. The machinists there regularly make complex propellers and foils for wind tunnel research, but their projects can range from mosquito experiments to dune buggy gear boxes.