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In the case of a multiple-launch rocket system firing in salvo, the rocket gas jet with different spacing will have different effects on the launch box. In this paper, the multi-barrel rocket launcher launch box was taken as the research object, and the development process of the double-launched and four-launched rocket gas jet impinging launch box under different spacing was numerically simulated. The results showed that under the double salvo, with the increase of the emission spacing, the speed of the gas jet increased, the degree of mutual interference decreased, and the surface pressure on the launch box gradually decreased. A smaller emission spacing would form a stronger airflow interference. The change trend of the four-shot salvo was similar to that of the double-shot salvo, and the change of the phenomenon is more obvious. This study provides a useful reference for further understanding the salvo law of rocket launcher and provides strong support for improving the performance of rocket launcher.

To meet the working requirements of the Rocket-Based Combined Cycle (RBCC) engine, a gas-oxygen/kerosene ejector rocket (strut rocket) is designed and experimentally studied. It was required to operate at a combustion chamber pressure of 2.0 MPa, oxygen-fuel ratio of 2.0, and a single rocket flow of 110 g/s. First, the strut rocket was designed, including the strut design with cooling channels, the rocket engine head design, and the thrust chamber design. The injector, panel, ignition, body thermal protection, and combustion performance were examined through the single component’s cold and hot firing test and the whole rocket. The test results show that the head injector can reasonably achieve the uniform mixing of gas/liquid propellant. The strut rocket can realize multiple stable and reliable ignitions, and there is no ablation at the throat of the thrust chamber, verifying the reliability of the thermal protection design. The rocket combustion efficiency can reach 97.8%, indicating that the strut rocket has excellent combustion performance.

The burning rate of solid propellant is a critical parameter influencing the performance and stability of rocket motors. This study experimentally investigates the burning rate of composite solid propellant used in dual-thrust rocket motors through both static firing tests and acoustic emission strand burner tests. A standard sub-scale 2-inch motor is employed to measure dynamic burning rate under varying combustion chamber pressure, while strand burner tests provide static burning rate measurements. The experimental results reveal a deviation between static and dynamic burning rates, attributed to erosive burning effects. Additionally, an internal ballistics prediction module (IBPM) is validated by comparing its outputs with static firing test data, demonstrating its applicability for performance prediction. The findings provide essential insights into the influence of combustion conditions on burning rate characteristics, targeting improved modelling and optimization of dual-thrust solid rocket motors (DTRMs).

In this research, a firing test was conducted on a Hybrid Rocket Motor (HRM) that operates using an aluminized solid propellant containing HMX and Hydrogen Peroxide (HP). The instantaneous regression rate of HRM is determined using reconstruction techniques, and the formula of regression rate is fitted by reconstruction techniques and traditional weight-loss method. The utilization of the reconstruction method presents a notable advantage, as it allows for the determination of the regression rate’s sensitivity to variations in oxidizer mass flux. Additionally, this method enables the fitting of the regression rate formula based on data obtained from a single firing test. The average value of regression rate of four times firing test are 0.944, 0.529, 0.595 and 0.486 mm/s. According to the weight-loss method and reconstruction techniques, the coefficients of determination ( R 2 ) of regression rate formula fitting are 0.8867 and 0.93 respectively, indicating that the accuracy of the fitting is better than that of traditional method. Overall, this paper presents a comparison of traditional weight-loss method and reconstruction techniques for providing a critical preference for the research of regression rate of HRM.

It is widely recognised that there is a global need for cheaper launchers for small satellites, and there is considerable global effort led primarily by private enterprise to develop these. One way to achieve these lower costs is to use cheaper materials, usually by sacrificing some of the performance benefit. A dual birectional double vortex bipropellant engine has been designed that confines combustion to the core of the rocket engine, thereby maintaining much cooler wall temperatures, enabling the employment of cheaper materials with lower melting temperatures. This paper reports on the design and successful test firing of such an engine with a nominal thrust of 20N, the first time that such an engine has been developed in an educational setting.

Traumatic brain injury(TBI) is one of the most common cause of major casualties in the battlefield. Soldiers may be endangering their brains when they operate certain shoulder-fired weapons or large-caliber artillery for long periods of time. It is necessary to pay attention to protection and prevention of brain injury in daily training. In this paper, the characteristic of shock wave propagation on the head with/without helmet protection when soldiers operated shoulder-fired rocket-propelled grenade launcher. The head-helmet surrogate was constructed in combination with pressure sensors. The pressure sensors were installed on the forehead, temples, top, and back of the head surrogate respectively and the sensors kept a plane with the surface of the head surrogate. The pressure variation of the shock wave flow field under different working conditions was analyzed in three types such as with/without combat helmet and integrated helmet. The results show that the peak overpressure of the shock wave from the back of the head can reach 80∼105kPa without combat helmet. The combat helmet can effectively reduce the shock wave overpressure. The integrated helmet has the best protection and can reduce the overpressure on the forehead, temple, top, and back of the head by 73%, 58%, 80%, and 83% respectively. Meanwhile the shock wave is prone to reflection and diffraction as it transmits inside the helmet. This significantly increase the overpressure of the shock wave on the forehead and the duration of the shock wave in the helmet, which has a negative effect on the protection provided by the shock wave.