Stability of Flow in a Rocket Motor

1950 ◽  
Vol 17 (3) ◽  
pp. 327-333
Author(s):  
D. F. Gunder ◽  
D. R. Friant
Keyword(s):  
Conformal Transformation ◽  
Rocket Motor ◽  
Fuel Tank ◽  
Analytical Treatment ◽  
Fuel Pump ◽  
Rocket Motors ◽  
Proper Design ◽  
Liquid Rocket

Abstract This paper presents an analytical treatment leading to a criterion for the proper design of liquid rocket motors to insure freedom from the phenomenon of “chugging” without unnecessary increase in fuel-tank or fuel-pump pressures. The most successful of the several methods suggested here is that of Nyquist, which involves a simple conformal transformation. The analytical treatment presented in this paper has been applied successfully in practice to eliminate this type of instability.

Holographic diagnostics of breakup phenomena of impinging jets for liquid rocket motor applications

1989 ◽  
Author(s):  
C. F. Hess ◽  
J. D. Trolinger ◽  
D. C. Weber ◽  
C. P. Wood ◽  
G. S. Samuelsen ◽  
...  
Keyword(s):  
Impinging Jets ◽  
Rocket Motor ◽  
Liquid Rocket

Modeling of Particulate Pressure in the Frame of Mesoscopic Eulerian Formalism for Compressible Reactive Dispersed Two-Phase Flows

2006 ◽  
Author(s):  
M. Simoes ◽  
O. Simonin
Keyword(s):  
Stokes Equations ◽  
Flow Region ◽  
Navier Stokes ◽  
Two Phase Flows ◽  
Two Phase ◽  
Specific Flow ◽  
Navier Stokes Equations ◽  
Rocket Motors ◽  
Eulerian Approach ◽  
Liquid Rocket

In space propulsion, compressible reactive dispersed two-phase flows are investigated in order to predict the behavior of solid or liquid rocket motors. In the frame of full Eulerian approach, physical modeling of aerodynamic flows in such motors is performed resolving unsteady compressible Navier-Stokes equations for both phases. However, numerical simulations performed on a simple axisymmetric motor have pointed out a flaw of this basic Eulerian approach. Indeed, the variance of the particle velocity distribution is not accounted for, leading to unrealistic accumulations of particles in some specific flow region. To correct this shortcoming, we have developed an advanced Eulerian model based on a statistical approach in the framework of the Mesoscopic Eulerian Formalism (MEF).

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 The position of liquid fuel residues in tank of worked-off rocket stage during ballistic descent

2021 ◽  
Vol 5 (1) ◽  
pp. 53-60
Author(s):  
V. Yu. Kudentsov ◽  
◽  
A. V. Kudentsov ◽  
Keyword(s):  
High Speed ◽  
Liquid Fuel ◽  
Side Surface ◽  
Fuel Tank ◽  
Rocket Fuel ◽  
Coverage Area ◽  
Fuel Component ◽  
Ballistic Trajectory ◽  
Liquid Rocket ◽  
Total Coverage

The results of modeling the behavior of liquid residues of the rocket fuel component in the fuel tank of the worked-off rocket stage on a ballistic trajectory are presented. The simulation is carried out for the following variants: during the controlled descent of the rocket stage and when using the technology of evaporation of liquid rocket fuel residues in the tanks of the spent stage. It is established that during the controlled descent of the spent rocket stage along the ballistic trajectory at the site of its turn and up to heights of 20 km, the liquid under the influence of overloads is distributed in the form of a film in the area of the bottom and side surface with a coverage area of up to 35 %. At the height of the maximum value of the axial overload, liquid fuel residues in the form of a film move to the area of the bottom and the adjacent side surface of the fuel tank. The total coverage area is about 22 %. The introduction of a hot coolant into the fuel tanks to vaporize the liquid remnants of rocket fuel radically changes the picture of the behavior of the liquid. Due to the high speed of the coolant in the tank, axial overload has little effect on the distribution of fuel residues in the rocket tank

Solid Propellant Rocket Motors

1961 ◽  
Vol 65 (604) ◽  
pp. 252-262
Author(s):  
W. R. Maxwell ◽  
G. H. S. Young
Keyword(s):  
Solid Propellant ◽  
Rocket Motor ◽  
Rocket Motors ◽  
Solid Propellant Rocket ◽  
Propellant Charge ◽  
Propellant Rocket

A solid propellant rocket motor consists essentially of a propellant charge in a container fitted with an expansion nozzle and igniter. Since, before a rocket motor can be designed, it is necessary to have some knowledge of the properties of the propellant to be used, a description will first be given of the propellants which are currently available.

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.

scholarly journals Numerical Analysis for Determination of Hydrodynamic Characteristics of a Gimbaled Thrust Vectoring Nozzle

2017 ◽  
Vol 41 (1) ◽  
pp. 69-84
Author(s):  
Saad Islam ◽  
Md Shafiqul Islam
Keyword(s):  
Stokes Equations ◽  
Rocket Motor ◽  
Navier Stokes ◽  
Hydrodynamic Characteristics ◽  
Navier Stokes Equations ◽  
Thrust Vectoring ◽  
Rocket Motors ◽  
Mach Number Distribution ◽  
Solid Rocket ◽  
And Control

Gimbaled thrust vectoring nozzles are employed in Solid Rocket Motors (SRM) to account for the aspects of maneuverability of the flight vehicle. The flow field of such a solid pulsed rocket motor is explored numerically (from dome-closeout onward) by solving Reynolds-averaged Navier-Stokes equations with Menter’s Shear Stress Transport (SST) k - ? turbulence model using a Computational Fluid Dynamics (CFD) tool. Parametric studies are carried out to find out the thermochemical and hydrodynamic characteristics of the hot gas in the rocket motor nozzle. The performances of different supersonic and subsonic sections were studied in terms of the hydrodynamic aspects such as static pressure and Mach number distribution. It is observed that the tradeoff of implementing thrust vectoring mechanism amounts to an additional pressure loss of 10.06% in the rocket motor. Such analyses are specific to certain types of Short Range Ballistic Missiles (SRBM) having solid state propellant (primary stage) in radial boost, end burning pulsed configuration with exacting demands on maneuverability and control implied upon payload and mission criterion.Journal of Bangladesh Academy of Sciences, Vol. 41, No. 1, 69-84, 2017

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.

Sign in / Sign up

Export Citation Format

Share Document