Tangential Impulse Detonation Engine Ionut Porumbel, Ph.D. Aerodays 2015 21.10.2015, London, UK
Overview Ongoing FP 7 project breakthrough propulsion system technology a step change in air transportation; Radically new approach propulsion power reduce weight, complexity, and cost; Significant reduction of overall fuel consumption and total amount of pollutants emission; Main idea: replacement of gas turbine by simpler system; Advantages: Reduction in engine weight; Removal of cycle maximum temperature limitation; Reduction of engine complexity: more reliability, lower costs, shorter manufacturing time; Reduction of engine size, particularly length; Practical solution to supersonic engine startup problem.
Engine components Fully rotating engine assembly; Upstream compressor connected to same shaft providing high pressure to combustor; Multiple rotating pulsed detonating combustors; Tangential exhaust of combustor flue gases to rotate entire combustor assembly through controlled direction nozzles; tangential velocity component drives rotating assembly axial component provides engine thrust
Expected progress Classical PDE design Proposed solution Detonation frequency of 10 Hz Efforts towards increasing it High energy, high frequency ignition spark plug carefully timed to PDC operation cycle Auto-ignition due to high Hydrogen flammability and using compressor outlet temperature and shock wave temperature increase The set of valves that open and close air, or air-fuel mixture admission in combustor suffer high wear, especially at high frequencies, and are subject to very high operating temperatures, and will induce pressure losses in the flow. Valveless designs, based on carefully timed pressure gradients in the flow, are an obvious goal for the future PDC development
High compression ratio compressor Further thermal efficiency increase Safe and stable combustion in valveless PDC Increased combustion efficiency and completeness Higher operating frequency Increased specific impulse More compact combustor Increased frequencies smooth out mechanical vibration Increasing compressi on of the fresh gases Increases the work obtained during the expansion process Inertial effects Requirements Improving compressor operating conditions
Compressor numerical simulations Steady RANS Unsteady RANS Constant outflow LES Variable outflow LES
Pulse detonation combustors Constant volume combustor operating under oscillatory conditions; Significantly more efficient than constant pressure Brayton cycle Speed of the burning process in detonation wave several orders of magnitude higher thermal efficiency further increases Thermodynamic efficiencies: 27% - Brayton cycle, 49% - detonation cycle Pollutant Emsions Production Lower Nox, no CO, CO2 and UHC significantly lower residence time Hydrogen very suitable detonation fuel Model Cycle efficiency [%] Ideal Real H 81.0406668 80.9132586 FJ 74.0201027 73.8016197 ZND 77.5410868 77.4844282
Reactive temperature Combustor numerical simulations Non-reactive shocks
Nozzles Nozzle shape optimization using VKI CADO optimizer thrust; maximization of Detonation flow conditions simulated by step rise in pressure, temperature and velocity straight tube detonation numerical simulations Performance evaluation under detonation conditions using DDTFoam; 2-D and 3-D numerical simulations carried out
Demonstrator design and manufacturing Detonation chamber (1); Semi casing (2); Resonator (3); Lateral wall (4)
Experimental program Campaign 1, Stage 1: non-reactive flow: Screening of over 50 possible configurations and temperatures at critical locations; instantaneous pressures Exclude solutions with incompatible geometries, fully subsonic flow, insufficient temperature rise. Campaign 1, Stage 2: reactive flow: Surviving configurations instantaneous pressures at same locations; Exclude solutions where repeatable detonation is not achieved. Campaign 2: reactive flow: Surviving configurations Select best configuration. Campaign 3, Stage 1: non-reactive flow: Best configuration Campaign 3, Stage 2: reactive flow demonstrator thrust and efficiency; instantaneous velocity measurements (PIV); Best configuration instantaneous velocity measurements (PIV) and flame front position (PLIF);
Conclusions and achievements Project scope limited and does not try to tackle all the problems raised by the new engine concept. Level 1 project planned to progress towards demonstrator engine; Demonstrate, both numerically and experimentally, that power provided by rotating PDCs can provide energy to drive compressor to required speed, with sufficient excess energy to power aircraft; Practical realization of compact, light, high efficiency, high frequency, self igniting PDC; Valveless PDC design, preventing detonation wave to propagate upstream; Maximum temperature limitation imposed by turbine material removed, allowing an overall increase in engine performance and efficiency; Expect to experimentally demonstrate high efficiency and thrust of designed PDC; Integrated solution for the proposed concept, validated through numerical simulation, and laying the foundation for building a demonstrator engine concept in the future.
Team Dr. Cleopatra Florentina CUCIUMITA Dr. Constantin Eusebiu HRITCU Dr. Bogdan George GHERMAN Dr. Valeriu DRAGAN Prof. Dr. Gabriel URSESCU Dr. Valeriu Alexandru VILAG Razvan CARLANESCU Prof. Dr. Guillermo PANIAGUA Dr. Bayindir Huseyin SARACOGLU Francesco ORNANO James BRAUN Prof. Dr. Johan REVSTEDT Dr. Weiwei LI Tudor CUCIUC