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.

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.

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.

Investigation of Liquid Breakup Process Solid Rocket Motor Part B: Vertical C-D Nozzle

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Wei-Lin Chen ◽  
Ahmad I. Abbas ◽  
Ryan N. Ott ◽  
Ryoichi S. Amano
Keyword(s):  
Froude Number ◽  
Droplet Diameter ◽  
Specific Impulse ◽  
Solid Rocket Motor ◽  
Solid Rocket Motors ◽  
Rocket Motors ◽  
Molten Droplets ◽  
Molten Particle ◽  
Computational Fluid Dynamics Cfd ◽  
Solid Rocket

Abstract Aluminized propellants are frequently used in solid rocket motors (SRMs) to increase specific impulse. However, as the propellant combusts, the aluminum is oxidized into aluminum oxide (Al2O3), it agglomerates into molten droplets that attach to the outside wall of the rocket nozzle. This phenomenon negatively impacts ballistics performance because the droplets remain attached to the inner wall of propulsion chambers. This buildup of particles tends to erode the wall, decreasing the performance and sustainability of the rocket. This study presents both experimental and computational fluid dynamics (CFD) to investigate the relationship between gas velocity and molten particle size for the vertically arrayed combustion chamber. Also, the Weber number and the Froude number are monitored to explain the breakup phenomenon and the condition of alumina flow in the whole testing channel. This study focused mainly on the vertical arrangement of the propulsion chamber with the cold experimental and simulation investigating the role of the liquid water in addition to a comparison with the horizontal chamber case. Unlike the horizontal setup, a greater number of droplets with smaller average droplet diameter present in the vertical setup; however, Froude number follows the same trend as for the horizontal C-D nozzle setup.

scholarly journals Parameters Affecting the Erosive Burning of Solid Rocket Motor

2018 ◽  
Vol 153 ◽  
pp. 03001
Author(s):  
Almostafa Abdelaziz ◽  
Liang Guozhu ◽  
Anwer Elsayed
Keyword(s):  
Burning Rate ◽  
High Energy ◽  
Rocket Motor ◽  
Solid Rocket Motor ◽  
Time Curve ◽  
Rocket Motors ◽  
Erosive Burning ◽  
Pressure Time ◽  
Burning Propellant ◽  
Solid Rocket

Increasing the velocity of gases inside solid rocket motors with low port-to-throat area ratios, leading to increased occurrence and severity of burning rate augmentation due to flow of propellant products across burning propellant surfaces (erosive burning), erosive burning of high energy composite propellant was investigated to supply rocket motor design criteria and to supplement knowledge of combustion phenomena, pressure, burning rate and high velocity of gases all of these are parameters affect on erosive burning. Investigate the phenomena of the erosive burning by using the 2’inch rocket motor and modified one. Different tests applied to fulfil all the parameters that calculated out from the experiments and by studying the pressure time curve and erosive burning phenomena.

scholarly journals Precise Design of Solid Rocket Motor Heat Insulation Layer Thickness under Nonuniform Dynamic Burning Rate

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Ran Wei ◽  
Futing Bao ◽  
Yang Liu ◽  
Weihua Hui
Keyword(s):  
Open Source ◽  
Burning Rate ◽  
High Performance ◽  
Traditional Approach ◽  
Computation Time ◽  
Solid Rocket Motor ◽  
Validation Data ◽  
Solid Rocket Motors ◽  
Rocket Motors ◽  
Solid Rocket

With the purpose of obtaining optimal designs of the heat insulating layers in solid rocket motors, we have proposed a numerical approach to compute the ideal thickness of the heat insulating layer. The proposed method is compatible with solid rocket motors that have any shape and any manner of erosion. The nonuniform dynamic burning rate is taken into consideration to achieve higher accuracy. A high-performance code is developed that uses triangular geometry as an input to allow exchanging data from any CAD platform. An improved geometric intersection algorithm is developed to generate the required sampling points, saving 35% computation time compared to its open source equivalent. Parallel computing technology is utilized to further improve the performance. All operations of the proposed approach can be executed automatically by programs, eliminating the manual work of gathering data from CAD software in the traditional approach. Validation data shows that the proposed approach saves 3.85% of the mass compared to the ordinary design approach. Performance profiling shows that the implemented code operates within 5 seconds, which is much faster than the unoptimized open source version.

Optimization of Solid Rocket Motor Quenching in Gas Dynamic Tunnels during Firing Bench Tests

2017 ◽  
Vol 743 ◽  
pp. 269-272
Author(s):  
Galina Ivanovna Shaidurova ◽  
Sergey Vladimirovich Patrulin ◽  
Aleksandr Aleksandrovich Nazartsev
Keyword(s):  
Environmental Safety ◽  
Design Parameters ◽  
Solid Rocket Motor ◽  
Solid Rocket Motors ◽  
Rocket Motors ◽  
Bench Tests ◽  
Gaseous Products ◽  
Gas Dynamic ◽  
Solid Rocket ◽  
Fuel Components

The paper presents the experimental results that allow determining optimum quenching conditions for solid rocket motors (SRM) at the stage of firing bench tests (FBT) in gas dynamic tunnels (GDT) with altitude simulation. The work describes main design approaches for quenching unit enabling reduced thermal insulation (TI) destruction by 15-20% after finish of SRM operation due to aftereffect decrease, as well as reduced values of scattering of TI undamaged layer thickness up to 10% owing to uniform cooling.If necessary, drying accompanied with emissions of TI gaseous products and remnants of k-phase fuel components is run in GDT, which allows improving environmental safety of working facilities and shortening the time for evaluation of SRM design parameters.

Using Machine Learning Algorithms on Prediction of Stock Price

2020 ◽  
Vol 12 (2) ◽  
pp. 84-99
Author(s):  
Li-Pang Chen
Keyword(s):  
Machine Learning ◽  
Stock Price ◽  
Short Term Memory ◽  
Machine Learning Algorithms ◽  
Machine Learning Techniques ◽  
Support Vector ◽  
Short Term ◽  
Learning Techniques ◽  
Historical Database ◽  
Long Short Term Memory

In this paper, we investigate analysis and prediction of the time-dependent data. We focus our attention on four different stocks are selected from Yahoo Finance historical database. To build up models and predict the future stock price, we consider three different machine learning techniques including Long Short-Term Memory (LSTM), Convolutional Neural Networks (CNN) and Support Vector Regression (SVR). By treating close price, open price, daily low, daily high, adjusted close price, and volume of trades as predictors in machine learning methods, it can be shown that the prediction accuracy is improved.

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