Design and Control of Solid-Fuel Ramjet for Pseudovacuum Trajectories
01 Sep 2000-Journal of Propulsion and Power (American Institute of Aeronautics and Astronautics (AIAA))-Vol. 16, Iss: 5, pp 815-822
TL;DR: In this article, the authors present a preliminary design of a propulsion system for an SFRJ-assisted gun-launched projectile and the methods to calculate the control requirements for this trajectory.
Abstract: A ballistic trajectory in air of a powered projectile where the thrust always balances the drag is termed as a pseudovacuum trajectory. For a solid-fuel-ramjet (SFRJ)-powered gun-launched projectile this trajectory can be achieved by the control of engine mass-e ow rate, either by a bypass control of inlet air or by a regression rate controloffuel. Based on one-dimensional considerations,theproceduresfora preliminary designofthepropulsion system for an SFRJ-assisted gun-launched projectile and the methods to calculate the control requirements are presented. Using these, typical cone gurations of SFRJ suitable for 155-mm gun-launched projectiles are analyzed for different launch angles. The results indicate that the control requirements by either method are minimal and thus, demonstrate the self-throttling characteristics of SFRJ.
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TL;DR: In this article, a literature survey about works related to numerical and experimental investigations on solid-fuel ramjet as well as using swirling flow and different numerical approaches has been provided, and a new and simple curvature/correction factor is proposed in order to reduce the programming complexity of SST-CC turbulence model.
20 citations
TL;DR: A comprehensive experimental investigation aimed at the examination of a solid fuel ramjet (SFRJ) regulation concept using an air-division valve has been conducted by controlling the ratio between the port and bypass flows, one can maintain a desirable working state over a wide range of flight conditions.
Abstract: A comprehensive experimental investigation aimed at the examination of a solid fuel ramjet (SFRJ) regulation concept using an air-division valve has been conducted By controlling the ratio between the port and bypass flows, one can maintain a desirable working state over a wide range of flight conditions A general regulation law based on maintaining a constant fuel-to-air ratio has been tested The experimental strategy was to isolate key parameters influencing the fuel regression rate, testing them one at a time, keeping the other parameters constant Experiments aimed at airflow rate, total air temperature and pressure, as well as port diameter effects, simulated a broad flight envelope, from Mach 15 to Mach 47 and from sea level to 13-km altitude The test results showed a very good agreement with the theory, demonstrating the feasibility, effectiveness, and characteristics of the air-division valve regulation technique in SFRJ motors
16 citations
TL;DR: In this article, a small-scale sealed laser ignition experimental system is set up to obtain the experimental measurements in the combustion process of Al/Mg fuel-rich propellants.
10 citations
01 Jan 2005
TL;DR: In this paper, an adaptive sliding controller is designed for velocity regulation of SFRJ in variable flight conditions and the results show that the controller showed a good performance in disturbance rejection which proves its robustness.
Abstract: This paper presents velocity control of a Solid Fuel Ramjet (SFRJ) in variable flight conditions. Since SFRJ is classified as an air breathing propulsion system its performance depends on the air flow over the solid fuel. Dynamic modeling of internal ballistics of SFRJ is developed using gas dynamic relations. This results in a set of nonlinear differential equations. The nonlinearity of equations comes from the fact that gas dynamic relations are generally nonlinear and since the value of some ballistic properties of SFRJ are inaccurate, uncertainties are available in dynamic equations. Then, an adaptive sliding controller is designed for velocity regulation of SFRJ. In order to design the controller the dynamic model is first identified using neural networks. Then the identified model is used to design the control system with the concept of sliding surfaces. The results show the effective performance of controller in velocity regulation of SFRJ in variable flight conditions. Also, the controller showed a good performance in disturbance rejection which proves its robustness.Copyright © 2005 by ASME
3 citations
19 Sep 2005
TL;DR: In this paper, a robust adaptive control based on the concept of sliding mode control using auto-tuning neurons is proposed for a solid fuel ramjet in varying flight conditions, which is applied to the system and its performance is shown through simulations.
Abstract: Modeling and control of a solid fuel ramjet in varying flight conditions is discussed in this paper. A set of nonlinear differential equations are derived to describe internal ballistics of the motor. Due to the complexity of the flow in SFRJ motor, some modeling parameters can not be exactly determined so some uncertainties are available in internal ballistics modeling of the SFRJ motor. A Robust control technique is developed for this system. The proposed controller is a robust adaptive control based on the concept of sliding mode control using auto-tuning neurons. The controller is applied to the system and its performance is shown through simulations
2 citations
Cites methods from "Design and Control of Solid-Fuel Ra..."
...Krishnan presented a preliminary design of the propulsion system for an SFRJ-assisted gun-launched projectile and the methods to calculate the control requirements for pseudovacuum trajectories [ 9 ]....
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References
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03 Feb 2020
TL;DR: In this article, the conservation equation for Inviscid flows is revisited: Velocity Potential Equation, Linearized Flow, and Time-Marching Technique for Steady Supersonic Flow.
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31 Oct 1977
TL;DR: In this article, the authors present a cycle analysis with losses: variation in gas properties diffuser pressure recovery compressor and turbine efficiencies burner efficiency and pressure loss imperfect expansion loss heat exchanger effectivness and pressure losses turbojet with losses turbofan with losses regenerated gas turbine with losses combined gas turbine-steam cycles with losses.
Abstract: Part 1 Introduction to concepts: thermal efficiency propulsive efficiency specific impulse and range ramjets turbojets turbofans turboprops and other shaft engines - regeneration stationary gas turbines - topping energy exchange, Mach number, and Reynolds number stresses noise thrust and drag fuels and propellants some engines in cutaway. Part 2 Ideal cycle analysis - trends: stagnation temperature and pressure the ramjet the turbojet the afterburning turbojet the turbofan the afterburning turbofan the turboprop thrust lapse cooling cycles the regenerative gas turbine gas turbines for topping the importance of turbine inlet temperature. Part 3 Cycle analysis with losses: variation in gas properties diffuser pressure recovery compressor and turbine efficiencies burner efficiency and pressure loss imperfect expansion loss heat exchanger effectivness and pressure loss turbojet with losses turbofan with losses regenerated gas turbine with losses combined gas turbine-steam cycles with losses. Part 4 Nonrotating components: topics in gas dynamics diffusers exhaust nozzles combustors and afterburners. Part 5 Compressors and fans: energy exchange, rotor to fluid compressor geometry and the flow pattern design choices based on blade section performance details of flow in transonic compressors stage performance - corrected parameters multi-stage compressors compressor and compression system stability centrifugal compressors supersonic-throughflow fan. Part 6 Turbines: turbine stage characteristics turbine blading turbine cooling turbine design systems turbine similarity. Part 7 Engine structures: centrifugal stresses gas bending loads on blades thermal stresses critical speeds and vibration blade flutter bearings engine arrangement and static structure. Part 8 Component matching and engine performance: compressor-turbine matching - the gas generator matching the gas generator and the nozzle multi-spool matching engine-inlet matching and distortion overall performance control and acceleration. Part 9 Aircraft engine noise: noise sources - unsteady flow jet noise turbomachinery noise noise measurement and rules. Part 10 Hypersonic engines: hypersonic inlets heat addition in high-speed flow heat release due to chemical reactions nozzle flow fuel injection and mixing quantitative discussion of scramjet performance cooling the scramjet the air turborocket the liquid-air collection engine. Part 11 Propulsion systems analysis: takeoff climb and acceleration cruise maneuvering.
375 citations
01 Mar 1976
TL;DR: In this paper, a detailed description of the equations and computer program for computations involving chemical equilibria in complex systems is given, and a free-energy minimization technique is used.
Abstract: A detailed description of the equations and computer program for computations involving chemical equilibria in complex systems is given. A free-energy minimization technique is used. The program permits calculations such as (1) chemical equilibrium for assigned thermodynamic states (T,P), (H,P), (S,P), (T,V), (U,V), or (S,V), (2) theoretical rocket performance for both equilibrium and frozen compositions during expansion, (3) incident and reflected shock properties, and (4) Chapman-Jouguet detonation properties. The program considers condensed species as well as gaseous species.
233 citations