Reliability analysis of torpedo loading based on fractional-order optimization model

A fractional-order cumulative optimization GM(1,2)model based on grey theory is proposed to study the relationship between torpedo loading and working reliabilities.In this model,the average relative error function related to order and background value is established.Taking the average relative error function as the objective function,the optimal value of the two parameters is obtained through the optimization method,and the minimum value of the average relative error is determined.The calculation example shows that this method can greatly improve the accuracy of the model and more accurately reflect the relationship between torpedo loading and working reliabilities compared with the traditional GM(1,2)model.

Maximizing the probability an aerial anti-submarine torpedo detects its target

As a result of the high speed of anti-submarine patrol aircraft as well as their wide range, high efficiency and other characteristics, aerial torpedoes released by anti-submarine patrol aircraft have become the key anti submarine tool. In order to improve operational efficiency, a deep study was made of the target detection probabilities for aerial torpedoes released by anti-submarine patrol aircraft. The operational modes of aerial torpedoes were analyzed and mathematical-simulation models were then established. The detection probabilities of three attacking modes were then calculated. Measures were developed for improving low probabilities of detection when attacking a probable target position. This study provides an important frame of reference for the operation of aerial torpedo released by anti-submarine patrol aircraft.

Maximum Force of Inclined Pullout of A Torpedo Anchor in Cohesive Beds

Torpedo anchors have been used in mooring systems for deep-water oil and gas projects owing to their prominent advantages, such as low cost and easy installation. The maximum force of torpedo anchors is crucial not only to the safety and stability of vessels and other marine facilities, but also for an economical design. It is necessary to develop reliable formula for fast predicting their maximum inclined force of a torpedo anchor in cohesive beds. In this study, the maximum inclined force of a torpedo anchor vertically embedded in cohesive beds was extensively investigated. 316 sets of inclined pullout laboratory tests were carried out for 9 differently shaped torpedo anchors which were vertically embedded in different cohesive beds. The loading curves were automatically acquisitioned and their characteristics were analyzed. The load angle relative to the horizontal varied from 20° to 90°. A new formula for fast calculating the maximum inclined force of the torpedo anchor vertically embedded in cohesive beds was obtained based on force analysis and a nonlinear regression on the data from the present and other studies. Effect aspects on the tests are discussed and further studies are highlighted.

Penetration Depth of Torpedo Anchor in Two-Layered Cohesive Soil Bed by Free Fall

The penetration depth of torpedo anchor in two-layered soil bed was experimentally investigated. A total of 177 experimental data were obtained in laboratory by varying the undrained shear strength of the two-layered soil and the thickness of the top soil layer. The geometric parameters of the anchor and the soil properties(the liquid limit, plastic limit, specific gravity, undrained shear strength, density, and water content) were measured. Based on the energy analysis and present test data, an empirical formula to predict the penetration depth of torpedo anchor in two-layered soil bed was proposed. The proposed formula was extensively validated by laboratory and field data of previous researchers. The results were in good agreement with those obtained for two-layered and single-layered soil bed.Finally, a sensitivity analysis on the parameters in the formula was performed.

Effects of torpedo blasting on rockburst prevention during deep coal seam mining in the Upper Silesian Coal Basin

In the Upper Silesian Coal Basin(USCB),coal seams are exploited under progressively more difficult geological and mining conditions(greater depth,higher horizontal stress,more frequent occurrence of competent rock layers,etc.).Mining depth,dislocations and mining remnants in coal seams are the most important factors responsible for the occurrence of rockburst hazards.Longwall mining next to the mining edges of neighbouring coal seams is particularly disadvantageous.The levels of rockburst hazards are minimised via the use of rockburst prevention methods.One active prevention method is torpedo blasting in roof rocks.Torpedo blastings are performed in order to decrease local stress concentrations in rock masses and to fracture the roof rocks to prevent or minimise the impact of high-energy tremors on excavations.The estimation of the effectiveness of torpedo blasting is particularly important when mining is under difficult geological and mining conditions.Torpedo blasting is the main form of active rockburst prevention in the assigned colliery in the Polish part of the USCB.The effectiveness of blasting can be estimated using the seismic effect method,in which the seismic monitoring data and the mass of explosives are taken into consideration.The seismic effect method was developed in the Czech Republic and is always being used in collieries in the Czech part of the coal basin.Now,this method has been widely adopted for our selected colliery in the Polish part of the coal basin.The effectiveness of torpedo blastings in the faces and galleries of the assigned longwall in coal seam 506 has been estimated.The results show that the effectiveness of torpedo blastings for this longwall was significant in light of the seismic effect method,which corresponds to the in situ observations.The seismic effect method is regularly applied to estimating the blasting effectiveness in the selected colliery.

Torpedo car tracking system at China Steel Corporation

Torpedo cars,for the hot metal transportation by rail,play an indispensable role in China Steel Corporation (CSC)'s production.In order to meet the requirements of continual progress in hot metal production and safety management,the torpedo car tracking system suitable for our identification has been built up.This system not only combines the applications of of radio frequency identification(RFID) for accurately locating and radio modems to transmit the torpedo car position data,but also integrates the monitoring of railway switch machines and level crossings as well as the torpedo cars management system.Accordingly all torpedo car positions and operation data of railway equipments can be displayed in the control center for the reference of the effectively monitoring of torpedo cars and the dispatching of missions.

An ideal point method adopting grey relational entropy to estimate life cycle cost with effectiveness of torpedo

To making the decision of the developing blue prints,ideal point method was selected to estimate the life cycle cost with effectiveness of torpedo.At the same time,the concept of grey relational entropy of the grey system theory was adopted to compute the distance between each blue print and the ideal point(or negative ideal point).The blue print,nearest to the ideal point and farthest to the negative ideal point,is the best one.As an example,four blue prints of torpedo were estimated.The result indicates the practical value of this method.

A capture probability analytic model for the electromagnetic launched anti-torpedo torpedo

With the unique characteristics,electromagnetic launch technology is applicable to launch shipborne anti-torpedo torpedo(ATT).This paper aims to establish an analytic model to pre-evaluate the capture probability of the electromagnetic launched ATT.The mathematics model of the multi-stage coilgun and the trajectory of the ATT is established for analysis.The influence factors of the capture probability are analyzed respectively,including the entry point dispersion of the ATT and the position dispersion of the incoming torpedo.Adopting the advanced angle interception mode,the ATT search model is obtained according to the positional relationship,and the course error is synthetically calculated according to the differentiation of implicit function.A geometric method to calculate the integral boundaries of the probability density function is proposed,based on the relative motion of the ATT and the incoming target.To verify the proposed integral model,the digital simulation and comparison is conducted.The results reveal that the variation trends and the calculation value of the proposed analytic model are coincident with the statistic results from Monte Carlo method.And implications of the results regarding the analytic model are discussed.

Interception probability simulation and analysis of salvo of two electromagnetic coil launched anti-torpedo torpedoes

Electromagnetic coil launch is an important branch of electromagnetic launch(EML)technology,which is suitable for launching anti-torpedo torpedo(ATT).This paper focuses on the EML parameters and the interception probability of the EML two ATTs salvo.Based on the launching model of a multi-stage coil launcher,the trajectory model of the ATT and the attacking torpedo,a calculation method for the EML two ATTs salvo parameters is proposed,with the conditions of capture and interception given reasonably.An adaptive particle swarm optimization(APSO)algorithm is proposed to calculate the optimal launching parameters,by designing the adaptive inertia weight and time-varying study factors.According to the analysis of the simulation with Monte Carlo method,EML will improve the interception probability effectively,and the interception probability is affected by the launching range.The results demonstrate good performance of the proposed APSO in calculating EML parameters for the two ATTs salvo in certain combat situation.Implications of these results are particular regarding the command and decision in the anti-torpedo combat.

A novel estimation algorithm for torpedo tracking in undersea environment

A novel estimation algorithm is introduced to handle the popular undersea problem called torpedo tracking with angle-only measurements with a better approach compared to the existing filters. The new algorithm produces a better estimate from the outputs produced by the traditional nonlinear approaches with the assistance of simple noise minimizers like maximum likelihood filter or any other algorithm which belongs to their family. The introduced method is extended to the higher version in two ways. The first approach extracts a better estimate and covariance by enhancing the count of the intermediate filters, while the second approach accepts more inputs so as to attain improved performance without enhancement of the intermediate filter count. The ideal choice of the placement of towed array sensors to improve the performance of the proposed method further is suggested as the one where the line of sight and the towed array are perpendicular. The results could get even better by moving the ownship in the direction of reducing range. All the results are verified in the MATLAB environment.

Cavity Flow Pattern Design for Supercaviting Torpedo

The flow pattern design of supercaviting torpedo,like the shape design of conventional bedewed torpedo,occupies an important position in torpedo system design.In this paper,the flow pattern design issues were studied systematically.A set of design criteria and main design requirements were proposed,and the design method and procedure were established.Moreover,the determination method of necessary parameters of cavitator and ventilated system for desired cavity flow pattern was given.Considered the speed and pressure disturbances in the torpedo navigation,a concept named margin design was proposed to solve the supercavitation deformation and instability caused by the disturbances.

Research on Influence of Damping Material on Structure Performance of Torpedo

Reducing the self-noise and radiated noise of torpedo is an effective way to enhance its detection and concealment capabilities.After discussing the basic principle on noise and vibration control and main noise sources in torpedo,the application of damping treatment for noise and vibration absorption was proposed in this paper.Compared composite materials(damping and metal materials)used as segment joint,their different contributions to the damping performance of base structure were investigated.The results show that the damping material can be used as segment joint effectively in vibration control.Taking cantilever beam as an example,four different damping treatments were compared in natural frequency and damping loss factor,the results show the influences of different damping layer layouts on the structure damping performance,and offer a reference for the torpedo shell design.

Modeling and simulation of torpedo acoustic homing trajectory with multiple targets

The characteristics of a torpedo＇s acoustic homing trajectory with multiple targets were studied. The differential equations of torpedo motion were presented based on hydrodynamics. The Fourth order Runge-Kutta method was used to solve these equations. Derived from sonar equations and Snell＇ s law, a simple virtual underwater acoustic environment was established for simulating the torpedo homing process. The Newton iteration method was used to calculate homing range and ray tracing was approximated by pieccwise line, which takes into consideration distortions cause by temperature, pressure, and salinity in a given sea area. The influence of some acoustic warfare equipment disturb the torpedo homing process in certain circumstances, including decoys and jammers, was alsotaken into account in simulations. Relative target identification logic and homing control laws were presented. Equal consideration during research was given to the requirements of rcal-timeactivity as well as accuracy. Finally, a practical torpedo homing trajectory simulation program was developed and applied to certain projects.

Design optimization of a torpedo shell structure

An optimized methodology to design a more robust torpedo shell is proposed. The method has taken into account reliability requirements and controllable and uncontrollable factors such as geometry, load, material properties, manufacturing processes, installation, etc. as well as human and environmental factors. The result is a more realistic shell design. Our reliability optimization design model was developed based on sensitivity analysis. Details of the design model are given in this paper. An example of a torpedo shell design based on this model is given and demonstrates that the method produces designs that are more effective and reliable than traditional torpedo shell designs. This method can be used for other torpedo system designs.

Conversion of Torpedo's Lake and Sea Test Data Based on Grey System Theory

As only a little information can be obtained from torpedo's lake and sea tests,and the torpedo's life does not distribute typically. If conventional methods are used to convert the environment factor for torpedo's lake and sea tests,their results can not reflect the actual conditions. A conversion model of the environment factor for torpedo's lake and sea tests is set up based on the GM(1,2) model of the grey system theory. For the merit of the grey system,the problem of uncertain life distributions and few samples can be solved. The calculation results show that the method is easy,realistic and high precise.

Torpedo Overall Multidisciplinary Design Based on Collaborative Optimization

A torpedo multidisciplinary design optimization (MDO) based on the collaborative optimization is proposed. Through decomposition and coordination, some problems in torpedo design such as multidisciplinary coupling, large data volume and complex data relationships can be solved. Taking aim at some complex problems in the torpedo design, such as computation in multidisciplinary design, organization, modeling and information exchange, the collaborative optimization methods based on approximate technology are presented. An example to increase the torpedo range is also given. It demonstrates that the method can converge quickly, has higher reliability and smaller data throughput, and is a very effective MDO method.

Design and Implementation of Simulation Environment for HLA-Compliant Torpedo Weapon System

A novel scheme for HLA(high level architecture)-compliant reconfigurable open architecture for the torpedo weapon system simulation is proposed.In addition,a kind of applied software framework for federate members based on the reusable software is put forward.The automation of time management strategy drafting and publish-subscribe declaration,and the consistent interface between RTI(run-time infrastructure) and simulation models are solved effectively.Furthermore,in order to simulate the fluctuant seabed,twinkle light spots,air bubbles,muddy effect,etc,an extended module,called as Underwater Space Vega,is developed.Finally,a distributed interactive simulation environment for underwater vehicles is set up with the aid of the software pRTI1.3.The preliminary experiment results indicate that this system friendly features GUI,reusable models and competence for real-time simulation.

Torpedo练习对高校女生游泳课教学效果的实验研究

为提高高校女生学习蛙泳的质量,为高等院校游泳教学课程的研究与发展提供建议,为游泳教师制定更为科学、合理且具有针对性的教学计划提供参考。以高等院校蛙泳教学课程为基点,引入Torpedo练习法,并设计实验对其效果进行研究,探讨该练习法对高校女性游泳初学者在身体素质和技术能力方面的影响。

空水跨介质鱼雷动力推进系统构型比较分析

目前外军装备的跨介质鱼雷均为助推运载器+鱼雷战斗部的构成形式,空水复用动力推进系统可使运载器与鱼雷合二为一,从而有效提高水下攻击有效载荷量与航程,且全寿命成本低廉,并有发展多次出入水功能的潜力。空水复用动力推进系统在常规鱼雷动力系统的基础上改造,使之具备空中推进和多模式切换的能力。文中针对3类可能的空水复用动力推进系统构型,从运行原理、系统性能、燃料选择、系统控制、研发难度以及发展潜力等方面展开讨论。研究结果表明,对于轻型跨介质鱼雷,可采用单一OTTO-Ⅱ燃料的构型,对于重型鱼雷则倾向于采用煤油和OTTO-Ⅱ双燃料双燃烧室系统的构型。

潜艇强机动变深规避鱼雷攻击仿真研究

潜艇利用强机动变深规避鱼雷末端攻击弹道是其规避鱼雷攻击的方法之一,也是潜艇防御鱼雷的最后措施。研究这种规避方法的可行性和有效性,可以为潜艇指挥员科学合理地操纵潜艇规避鱼雷攻击提供参考,对提高潜艇生命力和战斗力具有十分重要的理论研究意义和军事应用价值。通过对强机动规避方案基本原理及不同机动方式的效果进行理论剖析,并对潜艇和鱼雷相对运动态势进行建模仿真计算,验证了潜艇强机动变深规避鱼雷攻击的效果。仿真计算表明,在一定距离范围内,高速机动的潜艇利用高压气吹除主压载水舱的水,同时采用上浮大舵角使潜艇大尾倾高速上浮至水面来规避鱼雷末端攻击弹道,随后迅速下潜到浅水层完成规避鱼雷攻击,这种战术机动规避措施在理论上是可行的,但是该方案采用时机亦应当充分考虑分析。