Launching Process Research Articles

Structural design and dynamic characteristic analysis of adjustable badminton serving machine

System dynamics serves as a crucial foundation for evaluating the performance of mechanical auxiliary equipment. To enhance the stability and reliability of the badminton launch process, structural design and dynamic analysis were conducted on a mode-adjustable, precise control badminton serving mechanism. The combination of eccentric crank-slider mechanism, stretched springs, and electromagnets was used in mechanical structures, which could effectively effectively improve the smoothness of the badminton in the launching process. The virtual prototype of badminton serving machine was established and imported into ADAMS for dynamic simulation analysis, verifying the correctness of the serving and retrieving mechanisms. Using the aerodynamic equations, the trajectory of badminton movement under different working parameters was simulated and analyzed. The dynamic analysis results show that the design of the launching and catching mechanisms is scientific and effective. The launch angle and initial velocity are the key factors that determine the trajectory of the badminton.

Optimal Selection of Active Jet Parameters for a Ducted Tail Wing Aimed at Improving Aerodynamic Performance

The foldable tail of the box-type launch vehicle poses a risk of mechanical jamming during the launch process, which is not conducive to the smooth completion of the flight mission. The integrated nonfolding ducted tail proposed in this article can solve the problem of storing the tail in the launch box. Moreover, traditional mechanical control surfaces have been eliminated, and active jet control has been adopted to control the pitch direction of the flight attitude, which can improve the structural reliability of the tail wing. By studying the effects of parameters such as momentum coefficient, jet hole position, jet hole height, and jet angle on improving the aerodynamic performance of ducted tail wing, relatively good jet parameters are selected. Research has found that compared with jet hole height and jet angle, momentum coefficient and jet hole position are more effective in improving the aerodynamic performance of ducted tail wings. Under a trailing edge jet, a relatively good jet condition occurs when the jet hole height is equal to0.25% of the aerodynamic chord length, and the jet angle is equal to 0°. At this time, with the increase of the jet momentum coefficient, the effect of increasing the lift of the ducted tail wing is the best. Finally, a comparative analysis is conducted on the lift and drag characteristics between the ducted tail wing and traditional tail wing, and it is found that the ducted tail wing can generate lift at a 0° attack angle and will not stall in the high attack angle range of 12°~22°, with broad application prospects.

Coupled Modeling of Sea Surface Launch Flow and Multi-Body Motion

To simulate the launching process of missile complex flow, movement, and constraint states, a multifield coupling model is put forward based on a computational fluid dynamics (CFD) method. In this coupled model, a CFD method is used to solve the three-dimensional compressible transient flow, and the six-degree motion of the launching platform is considered, and the virtual contact method is used to deal with the constraint states of the guideway and the slider. The active force and moment are applied to the launching platform to simulate its rolling, pitching, and heaving motions under the 5-level waves. Collision detection is carried out through the minimum clearance distance between the slider and the guideway, and the contact force is handled by a modified Herz collision model. In the problem of launching a missile from the water surface, the change characteristics of the flow field, the load response characteristics, and the relative motion laws of the missile and the launching platform during the catapulting process are investigated. The results show that the motion laws of the projectile and the launch tube in the constrained direction are the same, and the established coupling model is able to simulate the launch separation process of the missile in the constrained state. In addition, the effect of wind load on the missile ejection process is analyzed using the coupled model.

A Compact All-Band Spacecraft Antenna with Stable Gain for Multi-Band GNSS Applications

This study presents a compact and stable gain spacecraft antenna that operates in all Global Navigation Satellite System (GNSS) bands from 1.164 GHz to 1.610 GHz. The proposed antenna structure based on the single-feed crossed bowtie antenna concept consists of four triangular patches excited with a 90° phase difference in between to generate right-hand circular polarization (RHCP), without needing complex feed networks. The radiator part of the antenna is covered by a radome and is also supported by a cylindrical dielectric cavity frame (DCF) to weaken the diffracted waves propagating along the ground plane while increasing vibration resistance. The fabricated antenna provides a return loss better than 10 dB with lower than 3 dB axial ratio and a stable gain around 7.2 ± 0.3 dBic over the entire GNSS bands, as well as a more compact and lightweight structural performance. It is also verified that the structural integrity and functional performance of the fabricated antenna remain consistent despite exposure to an equivalent vibration level in the launch process. The presented all-band spacecraft GNSS antenna is an innovative implementation with space industry insight for multi-band space applications that have application-specific limitations and provides consistent performance, as well as operational safety with the antenna design simplicity.

Web Application for Recommendation of Ayurvedic Drugs and Medicine using ML

This project aims to develop a comprehensive Ayurvedic drug recommendation website that seamlessly integrates traditional Ayurvedic principles with modern technology. The platform will cater to both students seeking educational resources and practitioners offering personalized healthcare guidance. The website's key features include drug prediction algorithms, herbal drug recommendations based on individualized assessments on symptoms, and a user-friendly interface. The initial phase involves meticulous planning, scoping, and research to define project objectives, target audiences, and select an appropriate technology stack. Subsequent weeks focus on design and prototyping, incorporating user feedback to ensure an intuitive and engaging interface. The front-end development phase emphasizes responsiveness and usability, while the back-end development integrates sophisticated algorithms for drug prediction and drug recommendation. User authentication and authorization mechanisms will be implemented to cater to both students and practitioners, ensuring a secure and personalized experience. The website's robustness and reliability will be validated through comprehensive testing, addressing any identified issues to guarantee a seamless user experience. The refinement and optimization phase involve continuous feedback collection, iterative improvements, and performance optimization. Beta testing will be conducted to gather user insights, refining the platform further. The deployment and launch process will involve hosting the website on a reliable platform, setting up monitoring tools, and officially releasing the Ayurvedic drug prediction and drug recommendation website to the public. This project combines the rich heritage of Ayurveda with cutting-edge technology, offering a valuable resource for education and healthcare in the Ayurvedic domain. The website aims to empower both students and practitioners with accurate drug predictions and personalized drug recommendations based on symptoms, fostering a holistic approach to healthcare that aligns with traditional Ayurvedic principle.

Research on the anti-ablation performance of TiC particle reinforced aluminum matrix composite coating

During the electromagnetic rail launching process, the severe ablation of the armature caused by the arc can easily lead to launch failure. Therefore, it is necessary to study methods of enhancing the anti-ablation property of the armature. One effective method is to prepare metal-ceramic composite coating on the surface of aluminium alloy armature. This paper conducts molecular dynamics simulation on the ablation protection effect of TiC particle reinforced aluminum matrix composite coatings on the aluminum armature substrate. By applying a surface Gaussian heat source to simulate the arc ablation effect, the micro-enhancement mechanism of TiC particles is analyzed through the depth of ablation craters, material mass loss, and the evolution of TiC particle morphology. The results show that the degree of material ablation intensifies with the increase of arc discharge power. The composite coating helps to improve the anti-ablation performance of the armature, and the anti-ablation performance first increases and then decreases with the increase of TiC mass fraction. The results can provide a theoretical foundation and technical support for optimizing design of anti-ablation performance of armature materials.

Numerical study on the motion characteristics of free fall lifeboats entering calm water and rough sea

As ocean engineering operations extend into deeper seas, the working environment becomes increasingly complex, making free fall lifeboats (FFLBs) more vital for maritime disaster rescues. Unlike traditional davit-launched lifeboats, FFLBs are propelled into the water at a specific velocity and angle, engaging in a complex motion process of launch, impact, submersion, and resurfacing. Therefore, to assess the safety of FFLBs, this paper regarding the lifeboat as a rigid body aims to investigate the six-degree-of-freedom motion characteristics of lifeboat entering the water with different entry angles θ and wave environment, with a specific focus on analyzing the primary causes of capsizing. The numerical simulations of water entry with various θ, wave heights H, and relative entry positions are carried out by combining large eddy simulation and overset mesh technology. The free surface is captured by the volume of fluid method, and the attitude change, acceleration change, motion trajectory, and free surface evolution law of lifeboats are analyzed. The findings suggest that lifeboats can enter calm water safely at θ of 20°–50° and maintain a stable posture. Moreover, in extreme conditions where θ is either 0° or 90°, there is a high risk of entry failure due to excessive vertical acceleration and poor motion attitude, respectively. Furthermore, when facing waves, lifeboats experience reduced horizontal displacement when entering at peak and downward zero point compared to calm water conditions, which poses challenges for avoiding potential dangers.

Experiences from launching the bridge over Gottleuba‐valley (Gottleubatalbrücke)

AbstractThis article briefly describes the project background, timelines, structural data, actually achieved milestones and current stage of project of the bridge over Gottleubavalley in Pirna, Saxony, Germany. The bridge is being built using incremental launching method, the main challenges of the launching process are briefly described together with some learning points.The winning design from the architectural competition in 2006 proposed very slender (1 to 35 !) hybrid steel‐concrete semi‐integral frame crossing the 70m deep and 1000m wide valley with nine spans (92 – 116 – 120 – 120 – 124 – 108 – 92 – 76 m) with maximum span length of 124m. The paper describes the challenges the team faced during the preparation and launching of a very slender bridge deck with deflections up to 6m when touching down at the bridge pier. By the time of the venue, the incremental launching will be already finished, and the lowering works will be in progress.

Repeated Partial Disruptions in a White Dwarf–Neutron Star or White Dwarf–Black Hole Merger Modulate the Prompt Emission of Long-duration Merger-type GRBs

The progenitors of gamma-ray bursts (GRBs) have long been an unresolved issue. GRB 230307A stands out as an exceptionally bright event, belonging to the long-duration GRBs but also exhibiting a late-emission component reminiscent of a kilonova. Together with the similar events GRBs 060614 and 211211A, they make up a new subgroup of GRBs with intriguing progenitors. If such long-duration merger-type GRBs originated from the coalescence of a white dwarf (WD) with a neutron star (NS) or a black hole (BH), as proposed in the recent literature, then the larger tidal disruption radius of the WD, together with a nonnegligible residual orbital eccentricity, would make repeated partial tidal disruptions inevitable. This may modulate the mass accretion and jet launching process at the NS or BH, resulting in a quasiperiodic modulation (QPM) in the light curve of the GRB, with a period equal to the orbital period. The detection of potential QPMs during the early episode of prompt emission of these three GRBs supports this scenario, and the relatively slow QPM (> 1 s) suggests that the lighter object cannot be an NS. We propose that the progenitor system of GRBs 230307A, 060614, and 211211A consist of a WD of mass 1.3 M ⊙, 0.9 M ⊙, and 1.4 M ⊙, respectively, and an NS (or BH). After several cycles of modulations, the WD is completely destroyed, and the accretion of the remaining debris dominates the extended emission episode.

Production and launch studies of cryogenic pellets for the ITER disruption mitigation system

A support laboratory has been set up to study pellet production, launch and shattering of cryogenic protium, deuterium, and neon pellets for the ITER disruption mitigation system, which plans to use 28.5 × 57 mm (diameter × length) protium, neon an mixture pellets in the Shattered Pellet Injectors. Such large protium pellets have not been produced and launched before, therefore the desublimation and launch process have been studied in detail in two steps. First 19 mm diameter pellets were produced, followed by the demonstration of the final pellet size. Pellet desublimation recipes were established for all pellet types, and it was found that, under certain conditions, even the large neon pellets can be launched with a propellant gas pulse, without requiring a mechanical punch device. This is attributed to cryogenic snow formation on the surface of the pellet. Conditions for the snow formation are studied and tendencies are understood using simple calculations.

Comprehensive simulation analysis of wave-induced dynamics and mesh adaptivity on submarine-launched missiles

Abstract Using the ANSYS simulation platform, we constructed a model of the underwater launching environment and submarine-launched vehicle (SLV) motion based on its launching environment and motion characteristics. We conducted numerical simulations using dynamic mesh technology to study the effects of waves on the attitude and pressure distribution of SLV during the launch process and to analyze the changes in its displacement, angle of rotation, force, as well as the perturbation rules of waves on SLV’s attitude during motion. This will provide a theoretical basis for the in-depth study of the impacts of underwater environmental factors on SLV launching.

Numerical simulation research on the launch process of pneumatic launch device

Abstract In order to deal with the potential threats posed by low-altitude UAVs, an anti-UAV net-catching device was designed based on the principle of pneumatic launch. The internal ballistic calculation model of the net-catching device during the launch process was established, and the pressure-stabilizing air chamber of the device was numerically simulated. The impact of pressure, air chamber volume, gas channel diameter and barrel length on the performance of the launch device to capture the UAV was analyzed. The internal relationship between different influencing factors on the muzzle velocity and the air pressure drop of a single shot was analyzed. Selecting appropriate internal ballistic characteristics to capture UAVs at different target distances provides theoretical guidance for in-depth research on anti-UAV netting devices.

Addressing Launch and Deployment Uncertainties in UAVs with ESO-Based Attitude Control

This paper describes the design and implementation of a novel three-axis attitude control autopilot scheme for tube-launched, air-deployed UAVs. In early flight tests, various factors, such as model uncertainties during launch, aerodynamic uncertainties, geometric parameter changes during deployment, and significant uncertainties in booster rocket installation, exceeded the control capabilities of the attitude autopilot, causing flight instability. In order to address these issues, a numerical simulation model of the full launch process considering deviations was established based on early flight tests. A cascade attitude controller was then designed using an extended state observer (ESO), and the boundedness of control errors under unknown bounded disturbances was theoretically proven, providing requirements for the parameter tuning of the cascade controller. Comparative experiments and a second flight test both demonstrate that the ESO-based cascade attitude controller exhibits strong feedforward disturbance compensation under high-uncertainty conditions, effectively achieving stable control within the flight envelope.

Local Deformation Analysis and Optimization of Steel Box Girder during Incremental Launching

Due to the significant weight of the steel box girder and the substantial gap between temporary piers, the stress concentration and localized deformation of the girder’s bottom plate are pronounced during the incremental launching construction process. In this study, the multi-scale finite element method was employed to simulate the incremental launching process of the steel box girder, analyze the pattern of localized deformation in the bottom plate contact area, and propose corresponding optimization control measures. Additionally, the entire incremental launching process was monitored, and the improvement in localized deformation before and after the optimization of the incremental launching scheme was analyzed. The results illustrate that the original incremental launching scheme led to substantial localized deformation in the bottom plate contact area of the steel box girder. Optimal control measures were implemented for the four incremental launching construction schemes. The optimal scheme significantly mitigated the localized deformation of the steel box girder’s bottom plate, with an average decrease in deformation of 48.32%. These findings can provide robust technical guidance and data support for the control of localized deformation in large-span steel box girders during the incremental launching construction process.

Recipes for pellet generation and launching in the ASDEX Upgrade SPI

In support of the ITER disruption mitigation system (DMS), a highly flexible, triple-barrel shattered pellet injection (SPI) system was installed at ASDEX Upgrade and tested in 240 dedicated discharges in the 2022 experimental campaign. Prior to the tokamak experiments, the system was commissioned and characterised in a laboratory environment. In this paper we discuss the experience gained from 2000 pellet launches on the freezing and launching process for 4 mm and 8 mm diameter pellets made from deuterium, neon and their mixtures. Different amounts of neon inside the pellet as well as the pellet heating recipes show a significant impact on pellet quality and successful launching. Pellet recipes were developed pushing the lower boundary of successful pellet launches. Depending on pellet size and composition, velocities between 60 m/s and 750 m/s were achieved.

Study on the Selection of Coil Energization Directions in Multistage Synchronous Induction Coil Launcher

In order to enhance the initial velocity and energy conversion efficiency of multi-stage synchronous induction coil launchers, the direction of coil energization for the drive coils is studied. There are typically two energization methods for multi-stage launching devices: (1) PP (Positive-Positive), where positive current is applied to all drive coils, and (2) PN (Positive-Negative), where currents in opposite directions are alternately applied to the drive coils. A finite element model of a four-stage coil launcher is established in ANSYS2022R2, and the acceleration effects of the armature under different inter-stage distances are analyzed for two energization methods. The study reveals that the PN configuration does not always result in higher armature velocities compared to the PP configuration under different inter-stage distances. The theoretical explanation is provided for the variations in the forces exerted by the previous and next drive coils on the armature during the acceleration process. It is found that the magnitude of the induced current in the previous and next drive coils during the launch process is influenced by the inter-stage distance, which in turn affects the electromagnetic thrust coupled with the armature. Thus, the method of determining the direction of current in the launching device coil is obtained.

Optimizing the infoproduct launch process: integrating the communication macrostrategy and paid traffic key performance indicators through the VERSALTO method

The global market, especially in the Digital Marketing area, has experienced enormous growth and a high degree of impact due to advances in technology, the growing number of smartphone users and the daily time spent using smartphones by these users. Within this market, the infoproducts sector has emerged as a specific and high-potential segment, directly connecting end consumers with information products, such as courses, mentoring, training, e-books and much more. The unique potential of this sector lies in its ability to overcome barriers that exist in other markets, making it possible to reach niche audiences and audiences on a global scale, often with low-cost operations and high return on investment (ROI). Despite the enormous potential of this emerging market, it lacks consolidated research on macro performance indicators in infoproduct operations, particularly the interaction between indicators of paid traffic operations and communication strategies, which directly affect the financial results of digital launches. In this context, this study aims to present the VERSALTO method, a framework designed to plan and analyze communication macro strategies and paid traffic indicators for infoproduct launches, demonstrating the interrelationship between these KPIs and the communication macro strategy, in addition to developing knowledge academic on the topic. To develop the method and demonstrate its practical application, this research analyzes two case studies with revenues exceeding 100 thousand Brazilian reais (20 thousand American dollars). Through this analysis, the interrelationship between paid traffic indicators and the communication macro strategy used in infoproduct launches was visualized. In this way, this study provides crucial insights for optimizing strategies and generating more profitable results in the dynamic digital marketing landscape.

SP-SAT: DEVELOPMENT OF AN EDUCATIONAL SATELLITE

n Bolivia, as in several other Latin American nations, there is a growing trend of burgeoning space projects and a rising interest among young students in the aerospace domain. Consequently, there arises an imperative to cultivate a new generation of space professionals. However, the exorbitant costs associated with the equipment utilized in these projects render them inaccessible to a vast majority of inter- ested students, including CubeSat kits, educational satellites, satellite kits, among others. Consequently, alternatives like educational sat- ellites have emerged to simulate the satellite design, construction, testing, launch, and operation processes on a scale conducive to student involvement. The primary challenge faced by students lies in integrating the essential subsystems of a satellite, encompassing power supply, sensors, and communication systems, within the confines of limited space. Considering this, the design and construction of an educational satellite with its respective signal reception equipment was developed. The equipment designed and manufactured is a low-cost one so that universities and educational centers could acquire it. This equipment educational kit is called SP-SAT (Space Program — educational satellite kit). This real satellite simulator offers a wide variety of educational activities. The kit’s equipment is distributed in two systems: 1) Space Segment, which consists of an Onboard Computer (OBC), Electrical Power System (EPS), Communications System (COMM), Experiment Plate (PYL), Complete PLA plastic structure (3D printed), rods, bolts, and nuts. 2) Ground segment: This segment includes all the equipment that is part of the ground station, which will receive data from the satellite.

Effects of cross flow on the launching process of submarine-launched vehicle considering the 6-DOF motion at barrel-exit stage

Submarine-launched vehicle (SLV) is a research hotspot due to its strong strike capability, among which underwater launching technology is a key issue hindering its development. In this paper, a numerical model is proposed to simulate the launching problem of SLV. The high nonlinearity induced by the coupling of multi-degree-of-freedom motions and the interaction between fluid and structure is solved. Specifically, the 6-DOF motion model of structure considering its strong added-mass effect, cavitation model and collision model are adopted. This numerical model is firstly validated by simulating the launching of SLV in still water. And then, the applicability of this model is discussed, as well as the effect of cross flow and initial launching velocity on the launching process. The results indicate that proposed numerical model could be used under both low-speed and high-speed cross flow situations. Cross flow changes the attitude and locomotion state of SLV. When flow velocity exceeds 1.25 m/s, the collision occurs between SLV (with the initial launching velocity of 40 m/s) and its barrel. This obtained locomotion of SLV after leaving its barrel causes the launching failure. Besides, a method of increasing launching velocity is introduced to promote the success rate of launching in high-speed cross flow situation.

Mechanisms of solid-liquid evolution and current-carrying characteristics at contact interface under the magneto-thermal effect

The contact state of the armature/rail (A/R) interface directly affects the launch performance and service life of the electromagnetic launcher (EML). Accordingly, this study employs the modified heat capacity method to construct a finite element model, considering the magneto-thermal effect based on electromagnetic field theory, energy conservation principles, Joule’s law, and frictional heat generation theory. The model simulates the solid-liquid evolution of the A/R interface during the electromagnetic launch process. The investigation elucidates the influence of the magneto-thermal effect on the electrical contact behavior of the interface by quantitatively analyzing how interface current-carrying characteristics change under different contact conditions. These findings offer fundamental insights for controlling the magneto-thermal behavior of the A/R interface in conditions of high-speed and high-current operation.