scholarly journals Comparison of cylindrical and non-cylindrical grain internal ballistic behavior of hybrid rocket engines and solid rocket motors

2021 ◽  
Author(s):  
Zhiliu Lu
Keyword(s):  
Specific Impulse ◽  
Propulsion System ◽  
Simulation Program ◽  
Rocket Engines ◽  
Hybrid Rocket ◽  
Ballistic Performance ◽  
Flow Process ◽  
Rocket Motors ◽  
Internal Ballistic ◽  
Propellant Rocket

Hybrid rocket engines (HREs) are a chemical propulsion system that nominally combine the advantages of liquid-propellant rocket engines (LREs) and solid-propellant rocket motors (SRMs). HREs in some cases can have a higher specific impulse and better controllability than SRMs, and lower cost and engineering complexity than LREs. For HREs and SRMs, both kinds of rocket engine employ a solid fuel grain, and the chosen grain configuration is a crucial point of their design. Different grain configurations have different internal ballistic behavior, which in turn can deliver different engine performance. A cylindrical grain design is a very common design for SRMs and HREs. A non-cylindrical-grain is a more complex grain configuration (than cylindrical) that has been used in many SRMs, and is also a choice for some HREs. However, while an HRE and an SRM can employ the same fuel grain configuration, the resulting internal ballistic behavior would not be expected to be the same. Pressure-dependent burning tends to dominate in SRMs, while axial flow-dependent burning tends to dominate in HREs. To help demonstrate in a more direct manner the influence of the differing combustion processes on the same fuel grain configuration used by an HRE and SRM, a number of internal ballistic simulations are undertaken for the present study. For the reference SRM cases looked at, an internal ballistic simulation program that has the capability of predicting head-end pressure and thrust as a function of time into a simulated firing is utilized for the present investigation; for the corresponding HRE cases, a simulation program is used to simulate the burning and flow process of these engines. For the present investigation, the two simulation programs are used to simulate the internal ballistic performance of various HREs and SRMs employing comparable cylindrical and non-cylindrical fuel grain configurations. The predicted performance results, in terms of pressure and thrust, are consistent with expectations that one would have for both propulsion system types.

scholarly journals Comparison of cylindrical and non-cylindrical grain internal ballistic behavior of hybrid rocket engines and solid rocket motors

2021 ◽  
Author(s):  
Zhiliu Lu
Keyword(s):  
Specific Impulse ◽  
Propulsion System ◽  
Simulation Program ◽  
Rocket Engines ◽  
Hybrid Rocket ◽  
Ballistic Performance ◽  
Flow Process ◽  
Rocket Motors ◽  
Internal Ballistic ◽  
Propellant Rocket

Hybrid rocket engines (HREs) are a chemical propulsion system that nominally combine the advantages of liquid-propellant rocket engines (LREs) and solid-propellant rocket motors (SRMs). HREs in some cases can have a higher specific impulse and better controllability than SRMs, and lower cost and engineering complexity than LREs. For HREs and SRMs, both kinds of rocket engine employ a solid fuel grain, and the chosen grain configuration is a crucial point of their design. Different grain configurations have different internal ballistic behavior, which in turn can deliver different engine performance. A cylindrical grain design is a very common design for SRMs and HREs. A non-cylindrical-grain is a more complex grain configuration (than cylindrical) that has been used in many SRMs, and is also a choice for some HREs. However, while an HRE and an SRM can employ the same fuel grain configuration, the resulting internal ballistic behavior would not be expected to be the same. Pressure-dependent burning tends to dominate in SRMs, while axial flow-dependent burning tends to dominate in HREs. To help demonstrate in a more direct manner the influence of the differing combustion processes on the same fuel grain configuration used by an HRE and SRM, a number of internal ballistic simulations are undertaken for the present study. For the reference SRM cases looked at, an internal ballistic simulation program that has the capability of predicting head-end pressure and thrust as a function of time into a simulated firing is utilized for the present investigation; for the corresponding HRE cases, a simulation program is used to simulate the burning and flow process of these engines. For the present investigation, the two simulation programs are used to simulate the internal ballistic performance of various HREs and SRMs employing comparable cylindrical and non-cylindrical fuel grain configurations. The predicted performance results, in terms of pressure and thrust, are consistent with expectations that one would have for both propulsion system types.

Design and Testing of a Lab-Scale Hybrid Rocket Motor to Evaluate Swirl Injection Characteristics

2018 ◽  
pp. 185-210
Author(s):  
Susane R. Gomes ◽  
Leopoldo J. Rocco
Keyword(s):  
Swirling Flow ◽  
Specific Impulse ◽  
Operating Conditions ◽  
Geometrical Parameters ◽  
Operating Pressure ◽  
Hybrid Rocket ◽  
Rocket Motors ◽  
Mathematical Background ◽  
Design And Testing ◽  
Firing Tests

This research aims to provide a methodology for the project of labscale hybrid motors. This development began with the thermal analysis of the fuel grain using the Flynn, Wall and Ozawa method, generating simulation entry data to maximize the motor performance. The simulation was performed with the Chemical Equilibrium Specific Impulse Code. Based on the optimum oxidizer to fuel ratio, the literature was used to supply the mathematical background to calculate the motor geometrical parameters whose operating conditions were determined throughout the simulation. Finally, firing tests were conducted to verify the reliability of the project methodology. The firing tests were performed with three injectors: two swirling and one axial. The tests showed that the higher the operating pressure the more suitable is the project, meaning the methodology developed works best in hybrid rocket motors with high operating pressures. Additionally, it was shown that the swirling flow injectors produce higher efficiency.

scholarly journals Hybrid Rocket Engine Design Optimization at Politecnico di Torino: A Review

Aerospace ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 226
Author(s):  
Lorenzo Casalino ◽  
Filippo Masseni ◽  
Dario Pastrone
Keyword(s):  
Design Optimization ◽  
Rocket Engine ◽  
Propulsion System ◽  
Future Perspective ◽  
Rocket Engines ◽  
Hybrid Rocket ◽  
Feed System ◽  
Research Activities ◽  
Multi Stage ◽  
System Design Optimization

Optimization of Hybrid Rocket Engines at Politecnico di Torino began in the 1990s. A comprehensive review of the related research activities carried out in the last three decades is here presented. After a brief introduction that retraces driving motivations and the most significant steps of the research path, the more relevant aspects of analysis, modeling and achieved results are illustrated. First, criteria for the propulsion system preliminary design choices (namely the propellant combination, the feed system and the grain design) are summarized and the engine modeling is presented. Then, the authors describe the in-house tools that have been developed and used for coupled trajectory and propulsion system design optimization. Both deterministic and robust-based approaches are presented. The applications that the authors analyzed over the years, starting from simpler hybrid powered sounding rocket to more complex multi-stage launchers, are then presented. Finally, authors’ conclusive remarks on the work done and their future perspective in the context of the optimization of hybrid rocket propulsion systems are reported.

Analysis of Smoke Agglomeration and Droplet Breakup in SRM

2011 ◽  
Vol 110-116 ◽  
pp. 691-697 ◽  
Author(s):  
Cong Lin Liu ◽  
Ye Gao ◽  
Zheng He
Keyword(s):  
Specific Impulse ◽  
Droplet Breakup ◽  
Heat Equations ◽  
Rocket Motors ◽  
Solid Propellant Rocket ◽  
Aluminum Droplets ◽  
Reaction Theory ◽  
The One ◽  
Breakup Model ◽  
Propellant Rocket

Modern solid-propellant rocket motors (SRM) are laden with aluminum powder to increase the specific impulse. In SRM chamber, on the one hand, aluminum droplets evaporate and burn to form alumina smoke, on the other hand, the alumina smoke agglomerates to droplets as droplets collide with each other. The agglomeration model is employed to simulate the burning droplets. And breakup model also used. To avoid complex reaction theory, the article solves the mass, momentum and heat equations of disperse and continuity phases to simulate the chemic reaction. Results showed that burning efficiency and agglomeration of droplet varied by different initial diameters, and the temperature as well as smoke concentration also changed, especially in nozzle inlet.

Numerical Investigation of a N2O/HTPB Hybrid Rocket Motor with a Dual-Vortical-Flow (DVF) Design

2017 ◽  
Vol 33 (6) ◽  
pp. 853-862 ◽  
Author(s):  
A. Lai ◽  
Y. C. Lin ◽  
S. S. Wei ◽  
T. H. Chou ◽  
J. W. Lin ◽  
...  
Keyword(s):  
Specific Impulse ◽  
Rocket Motor ◽  
Vortical Flow ◽  
Reacting Flow ◽  
Hybrid Rocket ◽  
Rocket Motors ◽  
Roll Control ◽  
Hybrid Rocket Motor ◽  
Fluid Properties ◽  
Rocket Performance

AbstractA compact hybrid rocket motor design that incorporates a dual-vortical-flow (DVF) concept is proposed. The oxidizer (nitrous oxide, N2O) is injected circumferentially into various sections of the rocket motor, which are sectored by several solid fuel “rings” (made of hydroxyl-terminated polybutadiene, HTPB) that are installed along the central axis of the motor. The proposed configuration not only increases the residence time of the oxidizer flow, it also implies an inherent “roll control” capability of the motor. Based on a DVF motor geometry with a designed thrust level of 11.6 kN, the characteristics of the turbulent reacting flow within the motor and its rocket performance were analyzed with a comprehensive numerical model that implements both real-fluid properties and finite-rate chemistry. Data indicate that the vacuum specific impulse (Isp) of the DVF motor could reach 278 s. The result from a preliminary ground test of a lab-scale DVF hybrid rocket motor (with a designed thrust level of 3,000 N) also shows promising performance. The proposed DVF concept is expected to partly resolve the issue of scalability, which remains challenging for hybrid rocket motors development.

scholarly journals Influence of propellant leakage from pump area into turbine area on turbo-pump operation stability

2021 ◽  
Vol 27 (1) ◽  
pp. 97-102
Author(s):  
M.V. Andriievskyi ◽  
◽  
Yu.O. Mitikov ◽  
Keyword(s):  
Combustion Engine ◽  
Specific Impulse ◽  
Liquid Oxygen ◽  
Stable Operation ◽  
Rocket Engines ◽  
Staged Combustion ◽  
Pump Operation ◽  
Operation Stability ◽  
The Stability ◽  
Propellant Rocket

There is an increasing trend to liquid-propellant rocket engines which run on eco-friendly storable propellant. This trend is mostly dictated by the refusal to use traditional toxic storable propellant in many countries. The most widespread eco-friendly storable propellant is hydrogen peroxide with kerosene. Though, this propellant has a lower specific impulse in comparison with traditional liquid oxygen with kerosene. To compensate the loss of specific impulse, there is a reason to design a staged combustion engine. Evidently, the turbopump is the most complicated system in the staged combustion propulsion system. This fact makes research devoted to turbo-pumps a top priority. The paper aims to determine the influence of propellant leakage from the pump area into the turbine area and create recommendations which would allow organizing the stable operation of turbopump. As a result of turbopump staged combustion cycle testing, a conclusion had been made that leakage, which opens during the test, significantly influences the stability of turbopump operation. Depending on the amount of leakage, the turbine generated power drop was between 20 and 45%, which led to a decrease in rotation speed and outlet pressure of the pump. During the R&D process, a way of leakage influence elimination had been offered. Formulated recommendations may be used during the design process of the turbopump for staged combustion liquid propulsion systems.

scholarly journals Theoretical Analysis of Ammonium-perchlorate Based Composite Propellants with RDX Containing Small Size Particles of Beryllium

2020 ◽  
Author(s):  
Paulo Alexandre Rodrigues de Vasconcelos Figueiredo ◽  
Francisco Miguel Ribeiro Proença Brojo
Keyword(s):  
Ammonium Perchlorate ◽  
Rocket Engine ◽  
Specific Impulse ◽  
Combustion Products ◽  
Rocket Engines ◽  
Oxygen Balance ◽  
Metallic Fuels ◽  
Ignition And Combustion ◽  
Operational Envelope ◽  
Propellant Rocket

Rocket engines have been developed for at least the last six decades. There is a need to improve the actual solid propellant grain for rocket engines through the addiction of metallic fuels in the mixture as well as the addiction of energetic binders to stabilize the combustion. The rocket industry expects the launchers to be reliable, to be faster, stable and to have longer times of operation for the most possible payload weight (operational envelope). New propellants should have optimized ignition and combustion time rates reducing the possibility of negative oxygen balance thus reducing detonation process. Deflagration process should be optimized for best performance of the rocket. In this evolution, small quantities of explosives have been used in the propellant in order to increase the operational burning time, hence, the specific impulse. Adding metallic fuels such as aluminum, boron or beryllium on double based composite propellants and ammonium perchlorate are expected to increase the propellant density over chemical stability and aging resistance. The study of heterogeneous propellants containing large amounts of fine beryllium and ammonium perchlorate,   it is necessary to understand the combustion products so to a proper evaluation of specific impulse, Mach number and mass flow of the mixture. In this study a mixture with nitramides (RDX – Cyclotrimethylene trinitramide) and ammonium perchlorate was analyzed with and without the addiction of small size particles of beryllium using a numerical algorithm. Therefore, this study relates the influence of beryllium  in the performance parameters of ammonium perchlorate based composite propellants. Keywords: Propellant, Rocket engine, RDX, Ammonium perclorate

Sign in / Sign up

Export Citation Format

Share Document