Impinging-jet injectors are commonly used in liquid-propellant rocket engines. Previous theoretical studies on sheets formed by two impinging liquid jets have largely ignored the affect of viscosity, however, several experimental results illustrated that viscosity could greatly influence sheet characteristics. This paper proposes an improved analysis model for viscous jets, which and energy dissipation taken into account; experiments were also performed to validate theory. Furthermore, based...

The present study focuses on characteristics of a liquid sheet resulting from the oblique collision two power-law fluid jets at low speed. Liquid expands radially impact point, forming bay-leaf-shaped bounded by thicker rim. A theoretical model for impinging is established. Sheet velocity distribution deduced through energy conservation during impingement; other features are predicted solving equations mass and momentum rim where equivalent viscosity proposed. shape diameter compared to...

The flying squirrel has a balanced amphibious ability on land and air, especially the to glide using their patagium, which makes it an excellent biomimetic object in design development of multimodal locomotion robots. This paper presents study aerodynamic characteristics pitching adjusting mechanism with deployed patagium. A 3D geometric model unfolded wing membrane was obtained scanning technique. Then simulation analysis based computational fluid dynamics software wind tunnel experiment...

Because theoretical research on unlike impinging injectors is lacking, a comprehensive model for proposed the study of spray characteristics. In this model, influences intermiscibility working fluids surface energy conversion and viscous dissipation are involved. Experiments impingement two types conducted compared with estimations, results exhibit good agreement. The effects tension mass diffusion coefficient sheet characteristics (shape, thickness, velocity distribution) also investigated.

The jumping–gliding robot is a kind of locomotion platform with the capabilities to jump on ground and glide through air. jumping this has juggle requirements initial velocity posture for entry gliding progressing ground. Inspired by flying squirrels, we proposed concept flexible wing-limb blending designed two modes. can takeoff different speeds stances, adjust aerial using swing forelimbs. To best our knowledge, first miniature bio-inspired that autonomically change stances when takeoff....

The spray characteristics of a liquid sheet contribute much to the investigation atomization efficiency. Considering jet contracting effect elliptical jets, an improved model power-law fluid jets is proposed herein derive characteristics. Some experiments have been conducted verify its feasibility, and results show good agreement with theoretical predictions. aspect ratio on shape thickness has studied interpret phenomenon that sheets formed by impinging are more likely disintegrate....

Abstract The nacelle and pylon structures of civil aircraft, due to their proximity the engine, are significantly affected by high-temperature components engine. To reduce impact high temperatures on internal systems, insulation blankets typically arranged inner side fan cowl, core bottom area decrease thermal transfer effect from engine hot air inside compartment structure. This paper mainly describes structural design method requirements for blanket, through analysis theoretical...

基于全波仿真得到的广义阵元有源方向图,该文提出一种用于综合多方向图共形阵列的新方法:自适应动态Meta粒子群优化(ADMPSO)算法。在传统Meta粒子群优化(MPSO)算法基础上,定义了优势子群和非优子群的概念,并通过植入非优子群裁减、优势子群规模膨胀以及惯性权重自适应更新等机制,实现了优化过程中多子群的自适应动态调整,全面提高了算法性能。ADMPSO成功用于12元微带锥面共形阵列非赤道面的多方向图综合,综合过程考虑了由共形载体导致的阵元极化指向各异特征,在公共激励存在约束情况下,使阵列同时实现了笔形、平顶,以及余割平方波束总功率方向图,其与该阵列全波数值仿真完全吻合,优化结果和收敛速度相比于其他算法均有显著改善。

Space Objects Identification(SOI) and related technology have aroused wide attention from spacefaring nations due to the increasingly severe space environment. Multiple ground-based assets been employed acquire statistical survey data, detect faint debris, photometric spectroscopic data. Great efforts made characterize different objects using data acquired by telescopes. Furthermore, detailed laboratory are needed optimize characterization of orbital debris satellites via material...

In recent decades, Fiber Reinforced Polymer/Plastic (FRP) has been successfully applied in varieties of structures due to its lightweight, high strength and corrosion resistance properties.In this paper, we developed a finite element model predict the behaviour 1.5 MW GFRP wind turbine tower by using SAP2000 software program, then orthogonal experiment optimum design methodology tower.The minimum self-weight was selected as performance target diameters wall thicknesses at top base were four...

A Multiple Independently Targeted Reentry Vehicle (MIRV) is a ballistic missile payload containing several warheads each capable of hitting one group targets. In the process flight control, release brings about coupling to attitude control system which will lower stability. order solve this problem, controller, combined α-order integral inverse with internal model principle, was presented. Firstly, determine Post Boost (PBV) dynamics model. Then, combine linearization equation feed-forward...

The simplistic infrared target observation feature is the main reason for that particle filter tracking algorithm are always failed. Considering limitations of description, we constructed an model based on high frequency features and features. template update method was also analyzed. Finally, designed flow combining gray feature. simulation results show proposed has good robustness accuracy in under complex background.