DLR-Logo -> http://www.dlr.de
DLR Portal Home | Imprint | Privacy Policy | Contact | Deutsch
Fontsize: [-] Text [+]

Hypersonic Boundary-Layer Transition on Cold-Wall Canonical Geometries with Quantified Distributed Roughness Elements

Surujhlal, Divek and Wagner, Alexander and Ponchio Camillo, Giannino and Martinez Schramm, Jan (2022) Hypersonic Boundary-Layer Transition on Cold-Wall Canonical Geometries with Quantified Distributed Roughness Elements. AIAA Journal, pp. 1-12. American Institute of Aeronautics and Astronautics (AIAA). doi: 10.2514/1.J062131. ISSN 0001-1452.

[img] PDF - Only accessible within DLR - Published version

Official URL: https://arc.aiaa.org/doi/10.2514/1.J062131


Given the challenges of obtaining a natural turbulent boundary layer on common test model geometries in a shock tunnel, this work aims to investigate the influence of roughness elements on the boundary layer with respect to transition to turbulence. The experiments were conducted in the High Enthalpy Shock Tunnel Göttingen at the German Aerospace Center on a 1100-mm-long, 7°-half-angle cone and a 602-mm-long flat plate at Mach 7.4. Roughness elements were applied on the nosetip of the cone and near the leading edge of the flat plate. The roughness elements were scanned with a laser profilometer, allowing their specification in terms of a roughness Reynolds number based on the 70th-percentile element height and an exceedance probability distribution. Transition was examined for the cone geometry using streamwise-aligned coaxial thermocouples on the 0° meridian. This assisted sizing the roughness elements required for transition to occur as far upstream as detectable. Breakdown of roughness-induced vortical structures generated by the roughness elements with a similar roughness Reynolds number was then examined using the flat plate geometry with temperature-sensitive paint applied downstream of the roughness elements. It was found that roughness-induced vortices required a finite distance (persistence length) to break down into turbulent structures. The persistence length was successfully reduced by interspersing roughness elements with smaller ones.

Item URL in elib:https://elib.dlr.de/189535/
Document Type:Article
Additional Information:Air Force Office of Scientific Research grant FA9550-17-1-0060 eISSN 1533-385X
Title:Hypersonic Boundary-Layer Transition on Cold-Wall Canonical Geometries with Quantified Distributed Roughness Elements
AuthorsInstitution or Email of AuthorsAuthor's ORCID iDORCID Put Code
Surujhlal, DivekUNSPECIFIEDhttps://orcid.org/0000-0002-0349-3328UNSPECIFIED
Wagner, AlexanderUNSPECIFIEDhttps://orcid.org/0000-0002-9700-1522UNSPECIFIED
Martinez Schramm, JanUNSPECIFIEDhttps://orcid.org/0000-0002-8891-6253UNSPECIFIED
Date:28 October 2022
Journal or Publication Title:AIAA Journal
Refereed publication:Yes
Open Access:No
Gold Open Access:No
In ISI Web of Science:Yes
Page Range:pp. 1-12
EditorsEmailEditor's ORCID iDORCID Put Code
Publisher:American Institute of Aeronautics and Astronautics (AIAA)
Keywords:Distrbuted roughness, boundary layer transition, hypersonic flows
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Space
HGF - Program Themes:Space Transportation
DLR - Research area:Raumfahrt
DLR - Program:R RP - Space Transportation
DLR - Research theme (Project):R - Reusable Space Systems and Propulsion Technology
Location: Göttingen
Institutes and Institutions:Institute for Aerodynamics and Flow Technology > Spacecraft, GO
Deposited By: Surujhlal, Dr. Divek
Deposited On:24 Nov 2022 10:19
Last Modified:29 Mar 2023 00:02

Repository Staff Only: item control page

Help & Contact
electronic library is running on EPrints 3.3.12
Website and database design: Copyright © German Aerospace Center (DLR). All rights reserved.