The design of hypersonic airbreathing vehicles is a challenging objective due to the intrinsic complexity propulsion-airframe integration in combination with an engine cycle able operate over wide Mach number range. This one objectives EC co-funded project LAPCAT-II aiming reduce antipodal flights less than 2 4 hours. Among several studied preceding LAPCAT-I, only aircraft designs for 5 and 8 were retained present project. Starting from available vehicle its related pre-cooled turbo-ramjet,...

A differential method is proposed to simulate bypass transition. The intermittency in the transition zone taken into account by conditioned averages. These are averages during fraction of time flow turbulent or laminar respectively. Starting from Navier–Stokes equations, continuity, momentum and energy equations derived for parts intermittent flow. turbulence described a classical k−ϵ model. supplementary parameter, factor, determined transport equation applicable zero, favourable adverse...

The extremely high heat loads within a scramjet combustor require the use of high-temperature materials combined with efficient cooling concepts. A promising technique is application transpiration to ceramic matrix composite materials. supersonic hot-gas-flow test facility used investigate this method. carbon/carbon samples tested have porosities about e = 11%. airflow electrically heated up 1120 K total temperature pressure ≈3 bar and accelerated Mach number 2.1 channel. Air, argon, helium...

To simulate transitional skin friction or heat transfer, the conditionally averaged Navier-Stokes equations are used. describe diffusion of freestream turbulence into boundary layer and intermittent laminar-turbulent flow behavior during transition, a weighting factor τ is A transport equation presented for this τ-factor including convection, diffusion, production, sink terms. In combination with conditioned equations, leads to an accurate calculation characteristics within layer. The method...

An air intake for a Mach 8 flight vehicle concept has been studied using large-eddy simulation with flow conditions corresponding to typical wind-tunnel tests. The contains several types of shock-wave/boundary-layer interaction which advantages over conventional Reynolds-averaged Navier-Stokes approaches. Laminar-to-turbulent transition was triggered localized blowing trips in the first external ramp surface close leading edge. lead turbulent spots that propagate within an otherwise laminar...

A concise overview of the overall layout an experimental powered high-speed flight vehicle including its subsystems is given. mission scenario, different segments and events to which payload is exposed are described justified. This allowed definition aero-thermo-mechanical loads required conceptually design all elements on board vehicle. The final configuration could achieve objectives. In particular aero-propulsive balance, i.e. thrust ≥ drag lift weight, be established at a cruise Mach...

The propulsion plant of a prospective supersonic cruise aircraft consists an air turbo-rocket expander and dual-mode ramjet. A comprehensive numerical model was constructed to examine the performance during acceleration vehicle. comprised one-dimensional representation fluid paths through ramjet, combustor, regenerator airframe-integrated nozzle, whereas turbomachinery bypass were included as zero-dimensional models. intake operation based on results time-averaged Euler simulations....

Liquid hydrogen has the potential to significantly reduce in-flight carbon emissions in aviation industry. Among most promising aircraft configurations for future hydrogen-powered are blended wing body and pure flying configurations. However, their tapered flattened airframe designs pose a challenge accommodating liquid storage tanks. This paper presents design guide conformable pressure tanks storage. The proposed tank feature multi-bubble layout subject low internal differential pressure....

Testing of the HyShot II scramjet configuration was carried out in High Enthalpy Shock Tunnel Goettingen, HEG, German Aerospace Center, DLR. Computational fluid dynamics (CFD) is applied to support analysis experimental results and for prediction free stream conditions HEG test section. Numerical simulations flow complete fuel on off were performed. This paper describes laminar turbulent modeling approaches CFD presents numerical their comparison experiment both nozzle reacting Scramjet. The...

This paper investigates the morphology of a flash-atomizing jet at conditions representative for rocket engine operations. Due to its relevance aerospace industry, both storable and cryogenic propellants are considered, namely ethanol [as inert equivalent monomethyl hydrazine (MMH)] liquid oxygen (LOx). A comparison between flashing behavior these two fluids is conducted. Despite differences in their physical properties, close similarity spray characteristics found terms shape, spreading...

The source terms in turbulence models require careful treatment to obtain a stable discretization. choice between implicit and explicit has be made. This can done either on the basis of individual or exact Jacobian terms. A comparison both methods shows that latter is generally applicable superior first, approximate method with respect convergence speed. comes from possibility using multigrid technique method, whereas this not always possible method. In principle, for robustness time-step...

Ground based testing of the HyShot II supersonic combustion ramjet flight configuration was carried out in High Enthalpy Shock Tunnel Gottingen, HEG, German Aerospace Center, DLR. The main focus these investigations was to obtain surface pressure and surface heat transfer data on intake cowl body side surfaces of the chamber nozzle. Further, high speed flow visualisation the combustor performed. Two HEG operating conditions which are related 33km and 27km altitude were applied....