Stability analysis of BOLT hypersonic flight experiment topic of H.S. Stillwell Memorial Lecture
Graham V. Candler is the speaker for the next H.S. Stillwell Memorial Lecture. The free lecture is hosted by The Grainger College of Engineering Department of Aerospace Engineering at the University of Illinois at Urbana-Champaign. It will be held on Monday, Oct. 21, at 4:00 p.m. in the auditorium on the first floor of the National Center for Supercomputing Applications at 1205 W. Clark Street, Urbana, Illinois.
Professor Candler is the Russell J. Penrose and McKnight Presidential Chair of Aerospace Engineering and Mechanics at the University of Minnesota.
The title of his presentation is, “Boundary Layer Stability Analysis of the BOLT Hypersonic Flight Experiment.
“The Boundary Layer Transition (BOLT) sounding rocket flight experiment will be launched in May of 2020,” Candler said. “BOLT is designed to make detailed measurements of the boundary layer state and the onset of transition to turbulence on ascent at about Mach 5 and on descent at Mach 7.5.
“BOLT has a complex nose geometry, highly swept leading edges and a concave surface, which challenge the validity of conventional stability analysis methods,” he said. “At the University of Minnesota we have been developing new approaches for predicting instability growth for complex geometry flows.”
Candler said in the Stillwell lecture he will discuss results and progress using high-order, low-dissipation numerical methods to perform “quiet” direct numerical simulations of the BOLT flow field.
“The simulations reveal four different instability mechanisms, including a vertical disturbance associated with boundary layer roll-up on the centerline, traveling crossflow due to boundary layer distortion near the leading edge, and a complex multi-mode instability near the trailing edge,” Candler said.
Comparisons to the available wind tunnel data will be presented. The prospects for extending the DNS to laminar flow break down and transition to turbulence will also be discussed.
Candler received his Ph.D. in Aeronautics and Astronautics from Stanford University in 1988. In his research, he supervised the development of the data-parallel line-relaxation method and the widely used NASA DPLR CFD code; he was instrumental in the development of the STABL boundary layer stability analysis tool, and its three-dimensional version, STABL-3D. He is a co-developer of the unstructured grid extension of the DPLR code, US3D, which is becoming a leading method for hypersonic and re-entry flow simulations.
He has used these simulation tools to study a wide range of supersonic and hypersonic flows, including supersonic parachutes, ablating re-entry vehicles, scramjet flow paths, and hypersonic transition processes with high-enthalpy effects.
Candler has published over 400 articles in various journals, conferences, and books. He was named an AIAA Fellow 2007. His many awards include the AIAA Dryden Lectureship in Research in 2018; the AIAA Fluid Dynamics Award in 2012; the Department of Defense National Security Science and Engineering Fellowship in 2009; the AIAA Thermophysics Award in 2007; AIAA Outstanding Paper in Aerodynamic Measurement and Ground Testing in 2006; the University of Minnesota George Taylor Distinguished Research Award in 2002; and the AIAA Best Technical Paper in Thermophysics in both 1990 and 2001.
As part of the Department of Aerospace Engineering's 75th anniversary year celebration, rather than a single lecture, it is offering four Stillwell Lectures, each in a different discipline within the field of aerospace engineering.
The H.S. Stillwell Memorial Lecture was established in honor of Professor H.S. (Shel) Stillwell. In 1944, when he was 27 years old, he founded the Department of Aeronautical Engineering at the University of Illinois at Urbana-Champaign and was the department head for 32 years. Stillwell was influential in the design of the first ramjet-powered missile and highly respected for his contributions to aerospace engineering education.