Results 21 to 30 of about 556 (201)

Machine learning and numerical investigation on drag reduction of underwater serial multi-projectiles

Defence Technology, 2022
To increase launching frequency and decrease drag force of underwater projectiles, a serial multi-projectiles structure based on the principle of supercavitation is proposed in this paper.
Xi Huang, Cheng Cheng, Xiao-bing Zhang
doaj   +1 more source

Experimental and Numerical Research on the Formation Conditions and Entrainment Characteristics of Supercavity by Rear Jet Reflux [PDF]

Journal of Applied Fluid Mechanics, 2022
Aiming at better controlling the ventilated supercavity flow for drag reduction, the experimental and numerical researches of supercavity by rear gas reflux are proposed in this paper.
B. Liu, M. Xiang, X. Zhao, W. Zhang, J. Li   +4 more
doaj   +1 more source

Design of Particle Swarm Optimization Adaptive Sliding Mode Controller Based on an Extended State Observer for the Longitudinal Motion of a Supercavitating Vehicle with Input Saturation

Journal of Sensors, Volume 2023, Issue 1, 2023., 2023
The aim of this paper is to present a novel sliding mode control scheme for the supercavitating vehicle trajectory tracking problem that subjects to external disturbances and actuator saturation with two symmetric elevators and a cavitator as actuators by analytical methods and computer simulations. Firstly, the nonlinear and highly coupled dynamic and
Guang Yang, Faxing Lu, Ling Wu, Junfei Xu, Nageswara Lalam   +4 more
wiley   +1 more source

Investigation on the effect of the flow passage geometry of diesel injector nozzle on injection process parameters and engine performances

Energy Science &Engineering, Volume 10, Issue 2, Page 552-577, February 2022., 2022
Nozzle modification – local hydraulic resistances (grooves) have been implemented on the needle tip of a serial nozzle to enhance the flow turbulence within nozzle, particularly at the orifice outlet. Benefits – the use of the modified nozzle No. 4 has achieved a 46.8% relative reduction of the smoke opacity and a 2.5% relative reduction of BSFC ...
Vladimir Markov, Bowen Sa, Vyacheslav Kamaltdinov, Vsevolod Neverov, Anatoly Zherdev   +4 more
wiley   +1 more source

Numerical Simulation and Experimental Research of Cavitation Jets in Dual‐Chamber Self‐Excited Oscillating Pulsed Nozzles

Shock and Vibration, Volume 2022, Issue 1, 2022., 2022
Self‐excited oscillating pulsed cavitation jet has many advantages, such as easy operation, simply maintenance, and low investment costs. Based on the structural parameters of the traditional Helmholtz and organ pipe single‐chamber self‐excited oscillating pulsed nozzles, Helmholtz + Helmholtz, organ pipe + organ pipe, and Helmholtz + organ pipe dual ...
Dongyan Shi, Yulin Xing, Lifu Wang, Zhuo Chen, Desmond Adair   +4 more
wiley   +1 more source

Numerical study of hot-gas ventilated supercavitating flow

International Journal of Naval Architecture and Ocean Engineering, 2022
This paper describes a numerical investigation of the characteristics of supercavitating flow using hot gas. The numerical results are validated through an experimental study under the same conditions at Chungnam National University Cavitation Tunnel ...
Van-Duyen Pham, Ji-Woo Hong, Ali Kareem Hilo, Byoung-Kwon Ahn   +3 more
doaj   +1 more source

Research on ventilation and supercavitation mechanism of high-speed surface-piercing hydrofoil

, 2022
Flow structures and hydrodynamic performance of high-speed surface-piercing hydrofoils were studied by numerical simulation, with an emphasis on the interaction mechanism between supercavitation and natural ventilation.
Yuchang Zhi, Xiao, Zhijian, Wang, Yiwei, Yiwei Wang, Zhendong Bian, Huang, Renfang, Tezhuan Du, Chenguang Huang, Zhi, Yuchang, Renfang Huang, Zhijian Xiao, Wang, Yongjiu, Bian, Zhendong, Huang, Chenguang, Du, Tezhuan, Yongjiu Wang   +15 more
core   +2 more sources

A study on the cavitating flow around an elliptical disk-shaped cavitator for non-body-of-revolution underwater vehicles

Engineering Applications of Computational Fluid Mechanics, 2023
Supercavitation has been recently presented as an effective method for the drag reduction of underwater vehicles. However, maintaining the supercavitating state requires a lot of energy, making vehicles difficult to control. Therefore, it is necessary to
Guangyao Chen, Tongshuai Sun, Shaoqiong Yang, Zhanzhan Miao, Hua Tan   +4 more
doaj   +1 more source

Composite Terminal Guidance Law for Supercavitating Torpedoes with Impact Angle Constraints

Mathematical Problems in Engineering, Volume 2022, Issue 1, 2022., 2022
A novel composite terminal guidance law with impact angle constraints is proposed for supercavitating torpedoes to intercept maneuvering warships. Based on an adaptive super‐twisting algorithm and nonsingular terminal sliding mode (NTSM), the proposed guidance law can guarantee the finite‐time convergence of line‐of‐sight (LOS) angle error and the LOS ...
Dongxue Xu, Jingyuan Zhang, Peng Wang, Xiaojia Yan, Haidi Dong, Xingling Shao   +5 more
wiley   +1 more source

Topologically protected optical pulling force on synthetic particles through photonic nanojet. [PDF]

Nanophotonics
Abstract A dielectric microsphere concentrates light into a photonic nanojet (PNJ), and swims towards the near‐infrared laser in response to the nanojet‐mediated force. In contrast, a Janus particle with an opaque metal layer was thought to be impossible to concentrate light into a stable nanojet.
Ren YX, Frueh J, Zhang Z, Rutkowski S, Zhou Y, Mao H, Kong C, Tverdokhlebov SI, Liu W, Wong KKY, Li B.   +10 more
europepmc   +2 more sources