Dr. Wagner's group at DLR has successfully pioneered the use of carbon-carbon (C/C) ultrasonically absorptive coatings (UAC) to delay hypersonic transition on a slender cone (Wagner et al., AIAA 2012-5865). C/C UACs are a very attractive passive hypersonic flow control technology due to their compatibility with practical thermal protection systems already found in hypersonic vehicles. Direct numerical simulations replicating the German experiments has been carried out by modeling the C/C UACs with the novel time-domain impedance boundary condition (TD-IBC) formulation developed by Scalo et al., Phys. Fluids (2015). Dr. Scalo's technique allows for the exact imposition in a Navier-Stokes solver of any physically admissible IBC. The required IBCs will be derived from a new campaign of C/C UACs acoustic absorption measurements. Their acoustic response will therefore be accurately modeled without the need to resolve or over-simplify the porous structure.
Direct Numerical Simulation of Hypersonic Transition Delay over Carbon/Carbon Ultrasonically Absorptive Coatings
2019
85 pages
Report
No indication
English
Coatings, Colorants, & Finishes , Acoustics , Fluid Mechanics , Coatings , Models , Hypersonic flow , Time domain , Acoustic impedance , Navier stokes equations , Acoustic absorption , Acoustic attenuation , Differential equations , Finite difference theory , Helmholtz equations , Transducers , Mach zehnder interferometers , Absorption coefficients , Sound waves , Broadband , Nonlinear dynamics , Dns (direct numerical simulation) , Dns modeling , Uac (ultrasonically absorptive coatings) , Transition control and modeling , Hypersonic transition delays , Cc (carbon carbon) , Cc uac , Td ibc (time-domain impedance boundary condition) , Cc porous surfaces , Second-mode waves , Hypersonic flared cones , Complex wall impedance , Hat (homogeneous absorber theory) , Wave angles
British Library Conference Proceedings | 2013
|British Library Conference Proceedings | 2013
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