Uncertainty Estimation in Large Eddy Simulations of Realistic Hypersonic Flows
Abstract
The main objective of this project has been to develop a systematic and computationally affordable method to estimate the uncertainty in the results of turbulence resolving simulations, particularly large eddy simulations (LES), of hypersonic flows. The work centered on the development of a method to compute the approximate sensitivity of engineering quantities-of-interest with respect to a large range of uncertain parameters, including insufficiently known boundary or initial conditions, unknown geometrical deviations between the physical and computational models, insufficiently fine computational grids, and inaccurate physics-models. The significance of the work is that it constitutes an important and necessary step towards enabling the use of LES in critical decision making, since the level of confidence in a decision (e.g., "does this design produce sufficiently low drag?") is directly tied to the level of uncertainty in the underlying prediction. The secondary objective of this project has been to further our understanding of how the near-wall region of turbulent wall-bounded flows is modified by changes in the Mach number and the wall temperature, and specifically to develop improved theoretical models for how the mean velocity profile scales with those changes. This type of near-wall scaling theory is directly used when estimating the wall friction and wall heat transfer in turbulent boundary layers, either in wall-models for LES or in engineer-type friction estimation methods.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 08, 2022
- Accession Number
- AD1231067
Entities
People
- Johan Larsson
Organizations
- University of Maryland