Missile Performance Research Articles

A comparative analysis of the aerodynamic performance of supersonic missiles with conical and ogive nose shapes

This paper presents a numerical study conducted to analyze the aerodynamic performance of supersonic missiles consisting of a cylindrical body and four flat-plate rear fins arranged uniformly, equipped with conical and ogive heads. Computational Fluid Dynamics (CFD) simulations were performed using the ANSYS Fluent 17.1 solver, along with the Gambit grid generation software. The objective was to compare the aerodynamic characteristics of these two head designs in terms of drag, lift, and stability at supersonic speeds. Various flow parameters, including Mach number and angle of attack, were investigated to comprehensively assess the performance of the missile configurations. The results indicate clear differences in the aerodynamic behavior of conical and ogive heads. Specifically, there was a 2–11 percent increase in the lift coefficient of the conical heads compared to the ogive heads, and an increase in the drag coefficient of both conical and ogive heads.

Memory-extraction-based DRL cooperative guidance against the maneuvering target protected by interceptors

This paper presents an open and interesting issue for missiles, i.e., achieving collaborative parameters constrained cooperative guidance, despite the interference of pursing interceptors (INTs) and the maneuvering target, by the fact that the target-missile-interceptor (TMI) engagement induces their complex and time-varying relationships. The Memory-Extraction-based Soft-Actor-Critic (ME-SAC) approach is proposed, which enhances the collaborative performance of missiles by implicitly extracting coupling motion characteristics among TMI from historical state, achieving the joint optimization of situation awareness and strategy. Firstly, the cooperative guidance task is formulated as a multi-order Markov decision process (MOMDP) to better represent the dynamic evolution of engagement, and a memory-extraction process is introduced to alleviate the curse of dimensionality. Secondly, a memory-decision-oriented maximum entropy framework combined with memory update modules is designed for enhancing strategy search ability. Then, a domain-knowledge-based pre-training is implemented to improve convergence speed. Finally, in simulation evaluation with various scenarios, the proposed ME-SAC shows more promising than the typical DRL-based and model-based algorithms in task success rate, learning efficiency, and adaptability.

Analysis of the aerodynamic performance of a hypersonic gliding missile with a deflected warhead

In this study, we propose a scheme to control the deflection of the warhead based on the configuration of the hypersonic glide body (HGB) to solve the problems posed by its large control surface load and severe aerodynamic heat under hypersonic flight conditions. We conducted numerical simulations on the configurations of deflection of the warhead of an HGB analog under different flight modes as well as varying angles and directions of deflection. The results showed that once the warhead had been deflected, the overall configuration of the HGB analog still exhibited static longitudinal stability. An increase in the angle of deflection significantly reduced the lift-to-drag ratio of the configuration at large angles of attack. When the warhead was deflected upward, the configuration of the HGB analog exhibited static lateral instability, while it exhibited a high static lateral stability when the warhead was deflected downward.

Silver-impregnated vanadium pentoxide nanofillers for reinforcement in titanium-based missile surfaces

An optimal content of silver doped vanadium pentoxide nanofillers (Ag-V2O5 NFs) was envisaged for reinforcement in Ti-based surfaces for boosting up the operational performance of high-supersonic and hypersonic missiles. Bar-shaped Ag-V2O5 NFs developed at 1, 3, and 5 % doping contents synthesized via microwave-assisted chemical solution technique were investigated for morphological, crystallographic, structural, and compositional properties by employing FESEM, XRD, Raman, and FTIR spectroscopy. Owing to their solubility differences, a blend of orthorhombic α- and β-phases were identified as spectral fingerprints specific to the developed Ag-embedded vanadium oxide crystalline structures. The Williamson-Hall method estimated the average crystallite size of α-Ag3-VO4 and β-Ag0.35-V2O5 phase NFs as 31.4 and 29.9 nm, respectively. The best results of the developed Ag-V2O5 NFs for the surface material transpired for the monoclinic metastable β-Ag0.333-V2O5 phase at optimal 3 % doping content with 13.7 nm average crystallite size, 0.35 % lattice strain, and 4.113 g/cm3 mass density.

A Static Stability Analysis Method for Passively Stabilized Sounding Rockets

Sounding rockets constitute a class of rocket with a generally simple layout, being composed of a cylindrical center-body, a nosecone, a number of fins placed symmetrically around the longitudinal axis (usually three or four), and possibly a boat-tail. This type of flying craft is typically not actively controlled; instead, a passive stabilization effect is obtained through suitable positioning and sizing of the fins. Therefore, in the context of dynamic performance analysis, the margin of static stability is an index of primary interest. However, the classical approach to static stability analysis, which consists in splitting computations in two decoupled domains, namely, around the pitch and yaw axis, provides a very limited insight to the missile performance for this type of vehicle due to the violation of the classical assumptions of planar symmetry and symmetric flight conditions commonly adopted for winged aircraft. To tackle this issue, this paper introduces a method for analyzing static stability through a novel index, capable of more generally assessing the level of static stability for sounding rockets, exploiting the same information on aerodynamic coefficients typically required for more usual (i.e., decoupled) static stability analyses, and suggests a way to assess the validity and shortcoming of the method in each case at hand.

INTRODUCTION OF THE «PREDICTIVE MAINTENANCE» CONCEPT TO INCREASE RELIABILITY AND PREDICTABILITY OF REPAIRS

This research article discusses the importance of implementing the Predictive Maintenance concept in the context of rocket and artillery weapons to improve the reliability and predictability of repair work. The article discusses key aspects of this concept, including its basic principles and methods, including the use of data analytics and artificial intelligence. The authors analyze the benefits of Predictive Maintenance in the military context, pointing to reduced repair costs, increased availability of military equipment, and extended equipment life. In addition, the article examines the challenges that arise when implementing this concept and provides recommendations on how to overcome them. Modern military equipment requires a high level of reliability and combat readiness. The introduction of the Predictive Maintenance concept is becoming extremely important to ensure the efficiency and safety of military equipment. This research article is devoted to the study and discussion of the possibilities of implementing Predictive Maintenance in the context of rocket and artillery weapons in order to increase the reliability and predictability of repair work. In conclusion, the article emphasizes the importance of implementing Predictive Maintenance as a strategic tool to ensure optimal performance and readiness of missile and artillery weapons in the modern military environment. Keywords: Implementation, concept, Predictive Maintenance, reliability, predictability, repair work, data analytics, artificial intelligence, monitoring systems, machine learning algorithms, sensors, failure prediction, planning, efficiency, readiness, rocket and artillery weapons.

Experimental study on the effects of interface dip angle on deformation failure of combined limestone–coal specimens

Uniaxial compression experiments of limestone–coal specimens at different inclination angles (0, 15, 30, 45, and 60°) were conducted using acoustic emission and three-dimensional, extension test digital image correlation, and full-field strain measurement systems to examine how dip angles affect deformation failure. The findings indicate that: (1) specimen groups demonstrate plastic yield characteristics in the pre-peak stage. However, slight variations exist due to inclination angles. (2) The localization zone for deformation evolution closely correlates to primary crack initiation and propagation within coal specimens and to slipping at the rock’s and coal’s interface. Failure in the coal specimen triggers rebound deformation in limestone when the rock coal inclination angle is set at 15°. Both the rebound deformation amount and its rate exhibit upward trends as a function of the inclination angle. (3) The percentage of pre-peak elastic property density in the combined specimen is augmented from 98.56 to 88.08% as the inclination angle augments and reduces to 75.80%. External energy’s conversion into missile performance shows an initial increase followed by a decrease. (4) The energy rate of the acoustic emission (AE) signal exhibits distinct temporal characteristics in the combined specimen that can be associated with quiet, active, and sudden increases.

Identification of Uncertain Parameter in Flight Vehicle Using Physics-Informed Deep Learning

This paper presents the estimation method for uncertain parameters in flight vehicles, especially missile systems, based on physics-informed neural networks (PINNs) augmented with a novel integration-based loss. The proposed method identifies four types of structured uncertainty: burnout time, rocket motor tilt angle, location of the center of pressure, and control fin bias, which significantly affect the missile performance. In the estimation framework, as neural networks (NNs) are updated, these uncertainties are also identified simultaneously because they are also included in the structure of NNs. After testing 100 simulation data, the average estimation errors are within 1% of the mean value for each type of uncertainty. The methodology is able to identify the parameters despite noise corruption in the time-series data. Compared with the conventional PINNs, adding the new loss based on the integration of differential equations yields a more reliable estimation performance for all types of uncertainty. This approach can be effective for complex systems and ill-posed inverse problems, which makes it applicable to other aerospace systems.

Effects of datalink target data on air-to-air missile performance

Modern air-to-air missiles rely on data updated via a datalink about the position and velocity of a target until their own seeker can lock on to the target. The quality of the datalink target data depends on the errors of position and velocity updates, delay of these updates and lost updates. This paper introduces a simulation framework for analyzing the utilization of this data. The framework consists of models describing the target, the missile, and the generation of the datalink target updates. The versatile simulation experiments presented in the paper analyze the effects of the quality of the datalink data on the performance of different air-to-air missiles. The measure of performance is the probability of kill. The results of the simulations imply that the quality of the final updates before attempting the transition to using the missile’s seeker have the largest effect on the performance. Unless a large percentage of the target updates are lost or the seeker’s lock on to the target is delayed, the missile can typically get within a lethal miss distance of the target. The framework presented in this paper is suitable for evaluating the performance of all types of guided weapons.

Investigation of the effect of nose shape and geometry at supersonic speeds for missile performance optimisation

This paper investigated and analysed the influence of the missile nose shapes and geometry on the drag force coefficients at supersonic Mach numbers ranging from 2 to 5. The nose shape investigation includes a pointed cone, pointed ogive, and blunt cone with a constant length and diameter of cylindrical afterbody. Subsequently, the nose length was manipulated to investigate how the nose geometry with different fineness ratios affected each drag component. The drag force coefficient and its components were determined using a program called MATLAB_Aerody, in which a semi-empirical approach was implemented for the calculations. The program was validated against the semi-empirical results with existing theoretical and experimental results. The comparison showed a maximum error of 3.6%. The results of the nose shape analysis show that a sharper and more slender nose with a pointy tip produces a minimal drag. Nose bluntness, however, creates considerable additional drag force due to a higher wave drag coefficient by forming detached or bow shock waves. At supersonic speeds, increasing the fineness ratio significantly reduces the drag force by drastically decreasing the wave drag coefficient with a marginal increase in the skin friction coefficients. However, the results show an insignificant additional gain for the skin friction drag and a reduction in the wave drag coefficient when the nose has a fineness ratio beyond 4.5. Furthermore, the results from both analyses show that the base drag coefficient is invariant with the nose shape and the fineness ratio. Therefore, a better missile performance can be achieved with a sharper and more slender nose shape with a higher fineness ratio.

New Result on Interception of Stationary Targets at Arbitrary Time-Varying Speed

This paper develops a novel approach and some main results on the varying-speed missile guided by pure proportional navigation (PPN) against a stationary target in the planar interception problem. The missile kinematic equation is established in the arc-length domain based on the differential geometry theory, which eliminates the influence of time-varying missile speed. Then, the closed-form solutions of line-of-sight (LOS) rate, leading angle, closing speed, and curvature command are derived in the arc-length domain. The performance of the varying-speed missile is analyzed, including the maximum relative distance, maximum curvature command, accurate path-to-go, and curvature increment. Additionally, the capture region is obtained considering the missile maneuvering acceleration limit. These new theoretical results could be extended to improve the performance of existing guidance laws designed under the constant-speed assumption.

Design and Analysis of a Deployment Mechanism with Clearance Compensation for High Stiffness Missile Wings

The deployment performance of the unfolded wing determines whether the winged missiles can fly normally after being launched, infecting the attack performance of the winged missiles. The paper proposes a new deployment mechanism with clearance eliminator. Based on the slider-crank principle, the proposed deployment mechanism achieves fast and low-impact deployment of the wings. The proposed clearance eliminator with shape memory alloy (SMA) effectively eliminates the clearance of the sliding pair and improves the support stiffness and stability of the deployed wing. The collision characteristics and the clearance elimination are studied for the deployment mechanism. The influence of the collision force on the motion state of the wing during the deployment is analyzed. The static stiffness of the wing under the clearance state and the deformation is analyzed. The dynamic stiffness under the catapult clearance elimination state is modeled based on the fractal geometry and contact stress theory. The relationship between the locking force and the support stiffness is revealed. The kinetic simulation is used to analyze the motion response during the action of the deployment mechanism. Modal analysis, harmonic response analysis, and random vibration analysis were conducted for the whole wings. A prototype was developed to verify the ejection performance of the wing according to the input load characteristics. The dynamic stiffness of the unfolded wings is tested by the fundamental frequency experiments to verify the performance of the clearance elimination assembly. The experimental results show that the designed deployment mechanism with clearance compensation achieves fast ejection and high stiffness retention of the missile wing.

Optimal Design of Multimissile Formation Based on an Adaptive SA-PSO Algorithm

In an effort to maximize the combat effectiveness of multimissile groups, this paper proposes an adaptive simulated annealing–particle swarm optimization (SA-PSO) algorithm to enhance the design parameters of multimissile formations based on the concept of missile cooperative engagement. Firstly, considering actual battlefield circumstances, we establish an effectiveness evaluation index system for the cooperative engagement of missile formations based on the analytic hierarchy process (AHP). In doing so, we adopt a partial triangular fuzzy number method based on authoritative assessments by experts to ascertain the weight of each index. Then, considering given constraints on missile performance, by selecting the relative distances and angles of the leader and follower missiles as formation parameters, we design a fitness function corresponding to the established index system. Finally, we introduce an adaptive capability into the traditional particle swarm optimization (PSO) algorithm and propose an adaptive SA-PSO algorithm based on the simulated annealing (SA) algorithm to calculate the optimal formation parameters. A simulation example is presented for the scenario of optimizing the formation parameters of three missiles, and comparative experiments conducted with the traditional and adaptive PSO algorithms are reported. The simulation results indicate that the proposed adaptive SA-PSO algorithm converges faster than both the traditional and adaptive PSO algorithms and can quickly and effectively solve the multimissile formation optimization problem while ensuring that the optimized formation satisfies the given performance constraints.

INDICATORS OF SA-19 “GRISON” ANTI-AIRCRAFT GUN MISSILE SYSTEM EFFICIENCY WHEN FIRING AT NONTYPICAL TARGETS OF THE ROCKET AND ARTILLERY WEAPONS

In modern conditions of combat use the SA-19 “Grison” anti-aircraft gun missile system fires at small targets (drones) and typical targets (helicopters and attack aircraft), so a number of problems arise. In particular, they include: finding the value of the probabilities of hitting the target with n shots and one shot; assessing the effectiveness of the SA-19 “Grison” platoon‟s concentrated fire on a single target; estimating errors of missile guidance and warhead detonation system; estimating the values of conditional probabilities of hitting a target with a single missile, depending on the value of particular mishit.
 When calculating the slant range to the far edge of the SA-19 “Grison” weapon's kill zone under different conditions of use, factors that reduce these ranges should be taken into account.
 An analysis of the main studies and publications presented in [1-9] does not make it possible to determine the performance of missile and artillery weapons in shooting at small-size targets. This literature provides general approaches to solving this problem.
 The purpose of this article is to develop a model for calculating the values of conditional probabilities of destruction of small targets, to form the best options for repelling an enemy‟s air strike, as well as to justify the general directions of improvement of weapon‟s elements.

A new physical pattern – consistency of the factor of dynamic relations between velocity vector modulus and longitudinal acceleration of missile warheads

The paper describes the existing problems in determination of all scheduled evaluations of missile warhead performance during flight tests and puts forward one of the possible methods of problem solving. Besides, the paper gives the results of investigation of the properties of the factor of dynamic relations between the velocity vector modulus and longitudinal acceleration of missile warheads within the atmospheric passive flight leg – the dynamic relation factor is constant in different flight test conditions. The notion of the reference dynamic relation factor is reasonably introduced for both parameters under study in order to provide reliable determination of parameter estimates, and hence, to conduct a complete analysis of experimental launch results.

Experimental and computational dynamic structural analysis of free-flight rockets

Aerospace vehicles’ designers often strive to approach the lightweight structures in order to improve flight performance without compromising vehicles durability. However, this goal may be achieved on the expense of structural rigidity of the vehicle. A missile with high slenderness ratio is a typical vehicle that should be considered as flexible body if precise dynamic behaviour analysis is sought. This analysis is crucial to identify the flight performance of such missile with high accuracy. The present paper discusses the results of a side-by-side experimental and numerical analysis of the vibration characteristics of a full-scale free-flight missile having 70mm caliber. The experimental modal analysis is conducted on the missile with empty motor to represent its unpowered flight regime. Experimental modal analysis setup involved accelerometer sensors while vibration excitation is achieved using an impact hammer. Modal analysis is also conducted numerically using a well-used high-fidelity commercial tool. Results of experimental modal analysis have shown that the first four modes as bending modes with frequencies of 134.4, 400.6, 819.4 and 1173.6 Hz, respectively. The results also demonstrate the close agreement between numerical and experimental approaches.

Analysis and Experimental Research on Test Method of Initial Guidance Thrust

With the gradual development of aerospace industry, the demand for missile performance is also growing. The steering gear, as one of the main implementing agencies of the missile guidance and control system, can adjust the actual thrust size through the closed-loop control system during missile guidance the deflection angle of the rudder surface, in order to change the missile's flight speed and flight attitude. The missile during the flight attitude correction and speed adjustment are through the electric servo output power to change the size of the output to complete. In this paper, the unsteady turbulent analysis theory is used to analyze the thrust test mechanism of jet. Through the simulation of the flow field, the influence of bearing wall position on the impact jet backflow zone location is studied, and the position of the bearing wall whose pressure value is the closest to the true value is determined. In addition, a simplified test system of jet thrust test was designed. The relationship between wall position and pressure was verified through experiments, which verified the accuracy of simulation results.

A hybrid model for predicting missile impact damages based on k-nearest neighbors and Bayesian optimization

Due to the increase of missile performance, the safety design requirements of military and industrial reinforced concrete (RC) structures (i.e., bunkers, nuclear power plants, etc.) also increase. Estimating damage levels in the design stage becomes a crucial task and requires more accuracy. Thus, this study proposed a hybrid machine learning model which is based on k-nearest neighbors (KNN) and Bayesian optimization (BO), named as BO-KNN, for predicting the local damages of reinforced concrete (RC) panels under missile impact loading. In the proposed BO-KNN, the hyperparameters of the KNN were optimized by using the BO which is a well-established optimization algorithm. Accordingly, the KNN was trained on an experimental dataset that consists of 254 impact tests to predict four levels (or classes) of damages including perforation, scabbing, penetration, and no damage. Due to the unbalance of the number of tests in each damage class, an over-sampling technique called BorderlineSMOTE was employed as a balancing solution. The predictability of the proposed model was investigated by comparing with the benchmark models including non-optimized KNN, multilayer perceptron (MLP), and decision tree (DT). Accuracy, F1-score, and area under the receiver operating characteristic (ROC) curve (AUC) were utilized to evaluate the performance of these models. The implementation results showed that the proposed BO-KNN model outperformed the other benchmark models with the average class accuracy of 68.05%, F1-score = 0.641, and AUC = 85.8%. Thus, the proposed model can be introduced as a foundation for developing a tool for predicting the local damage of RC panels under the missile impact in the future.
 Keywords:
 impact damage; k-nearest neighbors; Bayesian optimization; oversampling; imbalanced data; RC panel.

Aerodynamic Shape Optimization of a Missile Using a Multiobjective Genetic Algorithm

The aim of this paper is to demonstrate the effects of the shape optimization on the missile performance at supersonic speeds. The N1G missile model shape variation, which decreased its aerodynamic drag and increased its aerodynamic lift at supersonic flow under determined constraints, was numerically investigated. Missile geometry was selected from a literature study for optimization in terms of aerodynamics. Missile aerodynamic coefficient prediction was performed to verify and compare with existing experimental results at supersonic Mach numbers using SST k-omega, realizable k-epsilon, and Spalart-Allmaras turbulence models. In the optimization process, the missile body and fin design parameters need to be estimated to design optimum missile geometry. Lift and drag coefficients were considered objective function. Input and output parameters were collected to obtain design points. Multiobjective Genetic Algorithm (MOGA) was used to optimize missile geometry. The front part of the body, the main body, and tailfins were improved to find an optimum missile model at supersonic speeds. The optimization results showed that a lift-to-drag coefficient ratio, which determines the performance of a missile, was improved about 11-17 percent at supersonic Mach numbers.

Accuracy analysis and optimization of infrared guidance test device

As an important modern weapon, the development of infrared-guided missile reflects comprehensive national strength of a country. Therefore, it is especially important to establish a semi-physical simulation device to test the performance of missile, and the test device requires high accuracy. Based on the above background, an infrared guidance test device is designed in this article. The accuracy of its shell and rotating mechanism are studied in detail, and the error factors are quantified to provide theoretical basis for structural optimization. The orthogonal experiment design reduces the number of sensitivity analysis experiments on key design parameters. Factors affecting the maximum deformation and overall quality of the shell were determined. The range method was used to analyze sensitivity factors, and the final optimization result that met the minimum deformation and minimum quality was determined. Experimental results show that the rotation error of the main shaft of the rotating mechanism includes axial, radial, and angular motion errors, and experimental value is basically consistent with theoretical value. After the shell optimization, the infrared target pointing error [Formula: see text] and the infrared target position offset error ξ′ = 0.1525 mm meet the accuracy requirements. This method can provide new ideas for precision research and optimization of structural design of rotating mechanism.