scholarly journals Comparison Of Solid Rocket Motor Thrust Modulation Technique

2021 ◽  
Author(s):  
Clayton Edward Wozney
Keyword(s):  
Longitudinal Axis ◽  
Rocket Motor ◽  
Chamber Pressure ◽  
The Novel ◽  
Solid Rocket Motor ◽  
Nozzle Throat ◽  
Solid Rocket Motors ◽  
Rocket Motors ◽  
Lower Chamber ◽  
Solid Rocket

The thrust profiles of solid rocket motors are usually determined ahead of time by propellant composition and grain design. Traditional techniques for active thrust modulation use a moveable pintle to dynamically change the nozzle throat diameter, increasing the chamber pressure and therefore thrust. With this approach, high chamber pressures must be endured with only modest increases in thrust. Alternatively, it has been shown that spinning a solid rocket motor on its longitudinal axis can increase the burning rate of the propellant and therefore the thrust without the resulting high chamber pressures. Building on prior experience modelling pressure-dependent, low-dependent and acceleration-dependent burning in solid rocket motors, an internal ballistic simulation computer program is modified for the present study where the use of the pintle nozzle and spin-augmented solid rocket motor combustion approaches, for a reference cylindrical-grain motor, are compared. This study confirms that comparable thrust augmentation can be gained at lower chamber pressures using the novel spin-acceleration approach, relative to the established pintle-nozzle approach, thus potentially providing a significant design advantage.

scholarly journals Comparison Of Solid Rocket Motor Thrust Modulation Technique

2021 ◽  
Author(s):  
Clayton Edward Wozney
Keyword(s):  
Longitudinal Axis ◽  
Rocket Motor ◽  
Chamber Pressure ◽  
The Novel ◽  
Solid Rocket Motor ◽  
Nozzle Throat ◽  
Solid Rocket Motors ◽  
Rocket Motors ◽  
Lower Chamber ◽  
Solid Rocket

The thrust profiles of solid rocket motors are usually determined ahead of time by propellant composition and grain design. Traditional techniques for active thrust modulation use a moveable pintle to dynamically change the nozzle throat diameter, increasing the chamber pressure and therefore thrust. With this approach, high chamber pressures must be endured with only modest increases in thrust. Alternatively, it has been shown that spinning a solid rocket motor on its longitudinal axis can increase the burning rate of the propellant and therefore the thrust without the resulting high chamber pressures. Building on prior experience modelling pressure-dependent, low-dependent and acceleration-dependent burning in solid rocket motors, an internal ballistic simulation computer program is modified for the present study where the use of the pintle nozzle and spin-augmented solid rocket motor combustion approaches, for a reference cylindrical-grain motor, are compared. This study confirms that comparable thrust augmentation can be gained at lower chamber pressures using the novel spin-acceleration approach, relative to the established pintle-nozzle approach, thus potentially providing a significant design advantage.

Energy partitioning in high speed impact of analogue solid rocket motors

1999 ◽  
Vol 103 (1029) ◽  
pp. 519-528
Author(s):  
W. P. Schonberg
Keyword(s):  
High Speed ◽  
Failure Modes ◽  
Rocket Motor ◽  
Solid Rocket Motor ◽  
Solid Rocket Motors ◽  
Rocket Motors ◽  
Response Characteristics ◽  
Fast Running ◽  
Solid Rocket ◽  
Full Scale Tests

Abstract Modelling the response of solid rocket motors to bullet and fragment impacts is a high priority among the military services from standpoints of both safety and mission effectiveness. Considerable effort is being devoted to characterising the bullet and fragment vulnerability of solid rocket motors, and to developing solid rocket motor case technologies for preventing or lessening the violent responses of rocket motors to these impact loadings. Because full-scale tests are costly, fast-running analytical methods are required to characterise the response of solid rocket motors to ballistic impact hazards. In this study, a theoretical first-principles-based model is developed to determine the partitioning of the kinetic energy of an impacting projectile among various solid rocket motor failure modes. Failure modes considered in the analyses include case perforation, case delamination, and fragmentation of the propellant simulant material. Energies involved in material fragmentation are calculated using a fragmentation scheme based on a procedure developed in a previous impact study utilising propellant simulant material. The model is found to be capable of predicting a variety of response characteristics for analogue solid rocket motors under high speed projectile impact that are consistent with observed response characteristics. Suggestions are made for improving the model and extending its applicability to a wider class of impact scenarios.

Classification and Inspection of Debonding Defects in Solid Rocket Motor Shells Using Machine Learning Algorithms

2021 ◽  
Vol 16 (7) ◽  
pp. 1082-1089
Author(s):  
Xufei Guo ◽  
Yanwei Yang ◽  
Xingcheng Han
Keyword(s):  
Machine Learning ◽  
Layer Structure ◽  
Rocket Motor ◽  
Machine Learning Algorithms ◽  
Support Vector ◽  
Interface Debonding ◽  
Solid Rocket Motor ◽  
Solid Rocket Motors ◽  
Rocket Motors ◽  
Solid Rocket

Debonding problems along the propellant/liner/insulation interface are a critical factor affecting the integrity of solid rocket motors and one of the major causes of their structural failure. Due to the complexity of interface debonding detection and its low accuracy, a method of wavelet packet transform (WPT) combined with machine learning is proposed. In this research, multi-layer structure specimens were prepared to simulate the structure of a solid rocket motor. First, ultrasonic non-destructive testing technology was used to obtain defect data. Then, WPT algorithm was employed to extract characteristic signals of the defect data. Moreover, k-nearest neighbor model, Random Forest model and support vector machine model were applied to the classification. The results showed that the accuracies of the three models were 84.67%, 90.66% and 95.33%, respectively. Positive results indicate that WPT with machine learning model exhibited excellent classification performance. Therefore, WPT combined with machine learning can achieve a precise classification of debonding defects and has the potential to assist or even automate the debonding inspection process of solid rocket motors.

Solid Rocket Motor Internal Ballistics Simulation Considering Complex 3D Propellant Grain Geometries

2018 ◽  
pp. 146-169
Author(s):  
Guilherme Lourenço Mejia
Keyword(s):  
Solid Propellant ◽  
Structural Integrity ◽  
Combustion Process ◽  
Burning Surface ◽  
Chamber Pressure ◽  
Computational Tool ◽  
Solid Rocket Motor ◽  
Rocket Motors ◽  
Internal Ballistics ◽  
Solid Rocket

Solid rocket motors (SRM) are extensively employed in satellite launchers, missiles and gas generators. Design considers propulsive parameters with dimensional, manufacture, thermal and structural constraints. Solid propellant geometry and computation of its burning rate are essential for the calculation of pressure and thrust vs time curves. The propellant grain geometry changes during SRM burning are also important for structural integrity and analysis. A computational tool for tracking the propagation of tridimensional interfaces and shapes is then necessary. In this sense, the objective of this work is to present the developed computational tool (named RSIM) to simulate the burning surface regression during the combustion process of a solid propellant. The SRM internal ballistics simulation is based on 3D propagation, using the level set method approach. Geometrical and thermodynamic data are used as input for the computation, while simulation results of geometry and chamber pressure versus time are presented in test cases.

Correlation of graphite nozzle throat erosion in solid-rocket motors.

AIAA Journal ◽  
1968 ◽  
Vol 6 (11) ◽  
pp. 2222-2224 ◽  
Author(s):  
JOHN L. MAYBERRY ◽  
JAMES W. KORDIG ◽  
RICHARD J. ZEAMER ◽  
STANLEY C. BROWNING
Keyword(s):  
Nozzle Throat ◽  
Solid Rocket Motors ◽  
Rocket Motors ◽  
Solid Rocket

NUMERICAL SIMULATION OF INTRA-CHAMBER PROCESSES IN A SOLID ROCKET MOTOR WITH ACCOUNT FOR BURNING SURFACE MOTION

2021 ◽  
pp. 90-105
Author(s):  
A.E. Kiryushkin ◽  
◽  
L.L. Minkov ◽  
Keyword(s):  
Numerical Simulation ◽  
Numerical Algorithm ◽  
Burning Surface ◽  
3D Models ◽  
Stationary Regime ◽  
Rocket Motor ◽  
Chamber Pressure ◽  
Solid Rocket Motor ◽  
Solid Rocket ◽  
Motor Operation

The axisymmetric solid rocket motor (SRM) with an “umbrella” shape is considered in this paper. The numerical algorithm based on the inverse Lax-Wendroff procedure for a gas dynamic equation and on the level-set method for tracking the burning surface is overviewed for internal ballistics problems. Assuming that the propellant combustion proceeds in a quasi-stationary regime and a mass flow from the burning surface depends on the pressure raised to the power of parameter ν, the numerical computations of intra-chamber combustion product flows during the main-firing phase are carried out using the numerical algorithm developed for “umbrella”-shaped SRM at different parameter values. The approximation convergence of flow parameters in a case of the stationary propellant surface and average intra-chamber pressure for all the time of motor operation is examined. The numerical simulation results are obtained and analyzed for different “umbrella” inclination angles. Though the developed algorithm has been applied to the motors with a specific shape, it can also be used for propellant grains of different shapes and is easily extended to 3D models.

scholarly journals Numerical Study on Response Characteristics of Solid Rocket Pintle Motor

2019 ◽  
Author(s):  
Jeevan Sapkota ◽  
Yi Hua Xu ◽  
Hai Jun Sun
Keyword(s):  
Flow Field ◽  
Combustion Chamber ◽  
Total Pressure ◽  
Numerical Study ◽  
Rocket Motor ◽  
Chamber Pressure ◽  
Head Model ◽  
Solid Rocket Motor ◽  
Rapid Changes ◽  
Solid Rocket

Pintle technology is currently a versatile technology used in a solid rocket motor (SRM) to control the desired thrust by changing the nozzle throat area, while effectively controlling the chamber pressure at the same time. The sudden movement of the pintle can induce rapid changes in the flow field and the occurrence of pressure oscillations inside the combustion chamber. The analysis of such rapid changes is essential to design an efficient controllable pintle rocket motor for a better thrust regulation. Two-dimensional axisymmetric models with mesh generation and required boundary condition were designed to analyze the effects of three different pintle head shape models in SRM thrust regulation effect. Dynamic mesh method was used with specific velocity for moving plug/pintle in the numerical analysis of SRM thrust regulation. The effects of different pintle head models on the flow field, combustion chamber pressure, mass-flow rate, thrust and Mach number were investigated. According to the analysis of total pressure response time, the simulation data revealed that circular pintle head model responded faster among three different models. According to the thrust effect, parabolic pintle has the maximum value of thrust and the greatest total pressure recovery coefficient among all pintle head models.

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