contributor author | Nardini, Massimiliano | |
contributor author | Kozul, Melissa | |
contributor author | Jelly, Thomas O. | |
contributor author | Sandberg, Richard D. | |
date accessioned | 2024-04-24T22:49:56Z | |
date available | 2024-04-24T22:49:56Z | |
date copyright | 12/4/2023 12:00:00 AM | |
date issued | 2023 | |
identifier issn | 0889-504X | |
identifier other | turbo_146_3_031008.pdf | |
identifier uri | http://yetl.yabesh.ir/yetl1/handle/yetl/4295950 | |
description abstract | High-fidelity simulation of transitional and turbulent flows over multi-scale surface roughness presents several challenges. For instance, the complex and irregular geometrical nature of surface roughness makes it impractical to employ conforming structured grids, commonly adopted in large-scale numerical simulations due to their high computational efficiency. One possible solution to overcome this problem is offered by immersed boundary methods, which allow wall boundary conditions to be enforced on grids that do not conform to the geometry of the solid boundary. To this end, a three-dimensional, second-order accurate boundary data immersion method (BDIM) is adopted. A novel mapping algorithm that can be applied to general three-dimensional surfaces is presented, together with a newly developed data-capturing methodology to extract and analyze on-surface flow quantities of interest. A rigorous procedure to compute gradient quantities such as the wall shear stress and the heat flux on complex non-conforming geometries is also introduced. The new framework is validated by performing a direct numerical simulation (DNS) of fully developed turbulent channel flow over sinusoidal egg-carton roughness in a minimal-span domain. For this canonical case, the averaged streamwise velocity profiles are compared against results from the literature obtained with a body-fitted grid. General guidelines on the BDIM resolution requirements for multi-scale roughness simulation are given. Momentum and energy balance methods are used to validate the calculation of the overall skin friction and heat transfer at the wall. The BDIM is then employed to investigate the effect of irregular homogeneous surface roughness on the performance of an LS-89 high-pressure turbine blade at engine-relevant conditions using DNS. This is the first application of the BDIM to realize multi-scale roughness for transitional flow in transonic conditions in the context of high-pressure turbines. The methodology adopted to generate the desired roughness distribution and to apply it to the reference blade geometry is introduced. The results are compared to the case of an equivalent smooth blade. | |
publisher | The American Society of Mechanical Engineers (ASME) | |
title | Direct Numerical Simulation of Transitional and Turbulent Flows Over Multi-Scale Surface Roughness—Part I: Methodology and Challenges | |
type | Journal Paper | |
journal volume | 146 | |
journal issue | 3 | |
journal title | Journal of Turbomachinery | |
identifier doi | 10.1115/1.4063753 | |
journal fristpage | 31008-1 | |
journal lastpage | 31008-11 | |
page | 11 | |
tree | Journal of Turbomachinery:;2023:;volume( 146 ):;issue: 003 | |
contenttype | Fulltext | |