Projectile Explosion Research Articles

Fireball distribution characteristics and thermal radiation effects in the explosion of aviation kerosene storage tank

Aviation kerosene acts as the main fuel for civil and military aircrafts. In order to study the explosion fireball distribution and thermal radiation effects of aviation kerosene storage tank, the dynamic explosion test system was established. The development law of explosion fireball and the thermal radiation characteristics in the presence of various oil volumes (empty, bottom, half and full oil) under the dynamic impact of projectile were studied. The dynamic explosion process was divided into four stages: projectile explosion, aviation kerosene jet flow, aviation kerosene deflagration and pool fire. The evaluation model (Y=aXb) for maximum diameter, maximum height, duration of fireball and oil mass was established. The fireball temperature showed a trend of ‘rise-fall-rise-oscillation attenuation’. The maximum fireball temperature and average temperature increased first and then decreased as increasing the oil volumes, with the maximum values at 1534.67 K and 1285.78 K, respectively. Based on the fireball dynamic model, the damage effect of fireball thermal radiation on personnel was analyzed, the safety radius and injury probability were obtained, and the dynamic explosion fireball thermal radiation field was constructed.

Numerical Calculation Method of Target Damage Effectiveness Evaluation under Uncertain Information of Warhead Fragments

In order to scientifically evaluate the target damage effectiveness when warhead fragments formed by projectile explosion attack targets, this paper proposes a new method by using the multi-layer warhead fragments distribution division mechanism to study an evaluation and calculation model of target damage effectiveness under uncertain information of warhead fragments. On the basis of the spatial relationship between projectile explosion position and target, we first analyze the target damage rules based on the target’s own vulnerability characteristics. Then we use the fuzzy prior probability theory to establish the membership function of the target damage factor and an evaluation model of the target damage grade, and use the stochastic multi-criteria acceptability analysis method to obtain the evaluation index value of the target damage level. Finally, considering the ratio between the effective area of the warhead fragment group attacking target and the area of target itself and the effective number and area ratio of warhead fragments penetrating target, we give a numerical calculation method of target damage effectiveness. Through simulation and calculation, the results show that when the distance between the projectile explosion position and the target is less than 7 m and the coordinate interval of the projectile flight direction is −2.5 m to 2.5 m, the damage probability of warhead fragments to the target is greater than 75%. When the weight of the damage factor of the target changes, the damage effectiveness of the target also changes, and this result is in accordance with the actual experiment, which verifies the rationality of the proposed mathematical model.

Calculation model and analysis of fragment position with light field imaging mechanism under considering engineering uncertainty error factors

The spatial positions of multiple fragments formed by projectile explosion have random uncertainty dispersion state, so it is difficult to recognize each fragment and measure its spatial position when multiple fragments reach a certain area at the same time. In order to solve the problem, we propose a test method for measuring the spatial positions of multiple fragments based on dual light field intersection imaging mechanism, study refocusing principle of micro-lens array and four-dimensional light field imaging information, and establish the analytical model of spatial positions of multiple fragments. We set up the uncertainty error evaluation function of two light field cameras intersection test method from the perspective of engineering design, and give the uncertainty analysis method under engineering model. The influence of various factors on the uncertainty of test results under the engineering model is analyzed by calculation. Combined with the actual test data of the wooden target, the results show that the fragment spatial position test method based on dual light field intersection imaging mechanism is feasible and scientific.

Design of optical system of photoelectric detection sensor and flare signal processing with array lens

AbstractBecause the flare signal formed by projectile explosion is affected by the external environment, it is difficult for multi‐acoustic sensor array to obtain accurate synchronization signal. In order to solve this problem, this paper proposes a design method of ultra‐wide‐angle photoelectric detection sensor by using circular curved surface array lens, analyze the detection ability of photoelectric detection sensor with array lens, and establish the output signal function calculation model. According to the output signal of flare detection circuit, the feature points detection algorithm of modulus maxima based on wavelet transform is studied. Based on this algorithm, the signal is processed on the hardware processor to output the actual flare trigger control signal. The processing and recognition algorithm of signal mainly uses the relationship among wavelet modulus maxima, scale, Lipschitz index, and signal singularity to select the appropriate wavelet basis to process the flare signal formed by projectile explosion. Thus, the feature points of the flare signal singularity can be obtained. When the detection conditions of the feature points of the signal singularity are satisfied, the hardware outputs pulse signals to control the acoustic sensor array. The experimental results show that the designed detection algorithm of wavelet filtering and modulus maxima feature points can effectively detect the flare signal.

Space Projectile Explosion Position Parameters Measurement Method and Target Damage Probability Calculation Analysis

Because the random states of the projectile explosion position relative to the intersection target, the dispersion characteristics of warhead fragments are inconsistent, and it is difficult to provide a scientific calculation model of the target damage of warhead fragments formed by projectile proximity explosions. This paper studies a testing method of the projectiles explosive position using a combination of six screen sensors and an area array camera. We set up a calculation model of the projectile proximity explosion position parameters, which establishes the proximity explosion area probability of the projectile hitting the target. The calculation method of the target damage condition probability under the condition of firing multiple projectiles in one test was researched according to the dispersion characteristics of projectile proximity explosion, the damage area of the target, and the intersection condition of the projectile and the target. We also establish a target damage probability calculation model under the condition of an effective projectile proximity explosion hitting the target. The experimental results show that the target damage results of a theoretical simulation calculation and an actual projectile proximity explosion test data calculation were basically consistent. Moreover, the proposed target damage calculation model was verified under the probability of multiple projectile proximity explosions hitting the target.

Model Optimization and Calculation Method of Multi-Target Curved Motion Parameters Measurement Using Multi-Screen Intersection Test Mechanism

The parameters calculation model of a six-screen intersection with linear motion is used to test the projectile explosion location parameter under the condition of long-range artillery firing, which brings a significant test error, the main reason for the error is that the projectile has its own gravity during the flight, it makes the flight path of the projectile is a curved trajectory. To improve the test accuracy, this paper uses the projectile particle motion equation and six-screen intersection geometry relationship and considers the impact of the projectile's gravity acceleration and air resistance; it studies a calculation model and method of relative location for projectile proximity explosion under the spatial projectile curved motion. Then, it analyzes the error reason for calculating relative coordinate of projectile passing through the detection screen interval by using six-screen intersection test method based on linear motion. By introducing the gravitational acceleration and air resistance during the projectile flight process, establishes the variable trajectory parameters calculation model for a projectile with the curved motion passing through a six-screen intersection test system. Through the high-altitude projectile proximity explosion location test, this paper uses the method of the ballistic lateral camera to obtain the experimental data of projectile explosion location parameter. It compares the experimental data by using the six-screen intersection test method with linear motion and curved motion. The results show that the calculation model based on the curved motion model is closer to actual coordinate data of the projectile proximity explosion location.

Landing point location algorithm based on asynchronous time difference of arrival (ATDOA) method

This paper analyzes the acoustic and micro seism signal feature of the projectile launching, flight and landing explosion in range test, and puts forward a Landing Point Location method which based on the asynchronous time difference of arrival (ATDOA) method. This method can effectively filter away the signals in launching and flight process, meanwhile get the acoustic and micro seism signal of projectile explosion accurately, and then the explosion location and velocity can be obtained by iterative equations. Comparing with the existing projectile point positioning method, this method can find the arrival time of explosion signal accurately, and establish the composition equations by iterative calculation equation of the respective location without precise synchronization of each sensor. Accordingly, the complexity of the application system is reduced, and positioning precision is improved effectively.