VKI: Research Expertise Group on High Speed Propulsion & Combustion

General expertise of the research group

Utilisation of (liquid) hydrogen as propellant in airplanes or spacecraft, in combustion engines or thrusters:

• Combustion of hydrogen in turbines, for jet engines and for energy production
• (Pulsed) Detonation of hydrogen for aerospace propulsion

Specific hydrogen- related expertise & research topics

• Combustion models for thermodynamic modelling of hydrogen powered engines for hypersonic flight
• Numerical modelling, experimental validation
• Emission calculation
• Jet-noise modelling and testing

Available equipment/tools

• Facilities:
  • JAFAAR (Jet Aeroacoustic Facility for Aeronautical & Aerospace Research): the aeronautical applications concern mainly airframe noise with a focus on high-lift devices. The aerospace applications include launcher rocket noise, and supersonic boundary layer studies.The facility permits jet noise studies up to Mach 2, in single or a coaxial jet configurations with an outlet diameter of the order of 0.05 m. The flow is quietened by means of a silencer, and the jet discharges in an anechoic room with dimensions (4 x 3 x 4) m3 and with a cut-off frequency of 200 Hz. The facility can also accomodate a free-jet test section with side-plates for airframe noise research.
  • H3 (Mach 6 Hypersonic Wind Tunnel): the hypersonic tunnel H3 is a blow-down facility with an axisymmetric nozzle giving a uniform Mach 6 free jet 12 cm in diameter. Air is supplied at 7-35 bar stagnation pressure and a maximum 550 K stagnation temperature. Reynolds number may be varied from 3 x 106 to 30 x 106/m.
• Software & CFD platforms:
• Ecosimpro
• Fluent
• Chemkin
• WRF
• OpenFOAM®

Participating in FL/B/EU funded projects with H2 related research:

• [SPACE] PREDICT DREAMS is the continuation of PREDICT (experimental characterization of a slurry flow or densified cryogenic flow in hydraulic similitude with future cryogenic propellant at the triple point) in the framework of a PhD thesis. In this activity, both numerical simulation and experimental investigations are carried out. A CFD solver based on a Euler-Euler approach coupled with the Granular Kinetic Energy theory is in development, satisfactory results were obtained once validated against the PREDICT experimental data. The final ambitious goal targets experiments characterizing a slush flow and possibly evaluate the solver performances. Funding: FRIA/FNRS and ESA – NPI.
• [ENERGY] Be-HyFE (Belgian Hydrogen Fundamental Expertise): this project aims at developing a Belgian PhD network with PhD level research on hydrogen, about many different topics across the hydrogen value chain. The VKI PhD will focus on advanced characterization of thermodynamic properties of densified cryogenic hydrogen (or e-fuels more in general): composition (crystals shape and size), aging dynamics (stratification, melting), rheology and behaviour in pipelines and their components. This densified cryogenic slush is a promising solution to increase the volumetric density for storage and increase the resistance against boil-offs and heat losses during long distance transportation. Funding: Energy Transition Fund, by the Belgian Federal Public Services “Economy”.

International and industrial collaborations

• BOEING (USA)
• BOOM (USA)
• CiRA (UK)
• CNRS (FR)
• DLR (DE)
• Politechnico di Torino (IT)
• LUND University (SE)
• QinetiQ (BE / UK)
• TU Delft (NL)

Participating in FL/B/EU funded projects with H2 related research:

• STRATOFLY investigates the feasibility analysis of high-speed passenger stratospheric flight with respect to key technological, societal and economical aspects. The goal of STRATOFLY is to refine the design of a hypersonic vehicle able to fly at about 10,000 Km/h (Mach 8) above 30 km of altitude. The project will focus on the integration of innovative propulsion systems, unconventional structural configurations and systems for the thermal and energy management of the vehicle. Taking into account sustainability, the project will investigate strategies to reduce gas and noise emissions, while at the same time ensuring the required safety levels for passengers. The project aims at drastically increasing the efficiency of the thermodynamic cycle (>15%) by exploiting fuels cryogenically stored
  in the tanks. This efficiency gain will be quantified in terms of reduction of fuel consumption, emissions (75% to 100% reduction in CO2 emissions per passenger kilometer, 90% reduction in NOx emissions) and noise. Funding: EC – H2020. Partners: Politechnico di Torino, TUHH, UDC, CiRA, DLR
• MORE & LESS aims at MORE sustainable fuels, environmental protection and citizens protection, and LESS pollutant emissions, noise emissions and impact on air quality, ozone layer and climate: it aims at low-boom and environmentally sustainable supersonic aviation. The objective is to thermodynamically design and optimize 3 propulsion system components (inlet, turbomachinery and nozzle) for Mach 2 aircraft and for a Stratofly concept for Mach 5. MORE & LESS runs URANS simulations of hydrogen and bio-fuel combustion, for propulsion and pollutant emission determination. MORE & LESS performs aerodynamic testing, aeroacoustic jet noise modeling and experimental testing, and sonic boom propagation. Funding: Cleansky 2. Partners: Polito, BOOM, CIRA, CNRS, DLR, ECATS, FICG, INCAS, ISL, LUND University, BOEING, TU Delft, TUHH
• PDT aims at numerically and experimentally proving/disproving pulse-detonation thrustering as a viable option for spacecraft propulsion. After doing a thorough requirement review, 1D simulations on a number of viable solutions, and 3D CFD simulations, 2 PDT candidates are selected. With a trade-off analysis, the final PDT design is consolidated for testing. H2-O2 detonation experiments are performed under vacuum conditions, providing a vast amount of data to validate the numerical tools. Funding: ESA; partners: COMOTI, UPM, QinetiQ

Main relevant publications

1. Saracoglu B.H., Cutrone L., Marini M., Assessment of combustion models for thermodynamic modeling of the engines for hypersonic propulsion, International Conference on Flight vehicles, Aerothermodynamics and Re-entry Missions and Engineering (FAR) 30 September – 3 October 2019
2. Ispir A.C., Gonçalves P.M., Saracoglu B.H., Analysis of a combined cycle propulsion system for STRATOFLY hypersonic vehicle over an extended trajectory, MATEC Web of Conferences 304
3. Goncalves P.M., Ispir A.C., Saracoglu B.H., Development and optimization of a hypersonic civil aircraft propulsion plant with regenerator system, AIAA Propulsion and Energy 2019 Forum
4. Ali C. Ispir, Pedro M. Goncalves & Bayindir H Saracoglu, Thermodynamic efficiency analysis and investigation of exergetic effectiveness of STRATOFLY aircraft propulsion plant, by., AIAA 2020-1108, January 2020