The high-speed water-entry phenomenon of vehicles with a free and constant speed is numerically studied. different behaviors the cavities created by vertical water entry projectiles nose shapes, tail impact speeds are investigated. drag characteristics or compared. flow field compared analyzed. Unlike cavity induced free-speed entry, that constant-speed more stable maintained for longer time. expansion projectile can weaken effect re-jet flow, generated seal, on head prolong attachment time...

Abrasive water jet (AWJ) is a type of cold processing technology, and there are many factors affecting its machining effect. In this paper, coupled Finite Element Methods-Smoothed Particle Hydrodynamics (FEM-SPH) numerical model was established to investigate the key influencing AWJ ductile materials. The abrasive particles in were shaped as irregular polyhedrons, material properties well influence mechanism fluid–structure interaction between considered. relative error range experimental...

The past research on the supercavity flow mostly focused homogeneous fluid medium, ignoring influence of sudden change medium density. We present results from numerical study moving projectile passing density zone, both low-density zone to high-density and low-density. Particular attention is given cavity variation when voyaging through different liquid areas. And cavitation number also studied. Research show that there a ‘diameter shrinkage’ phenomenon pass jump area. location relative...

Previous studies on supercavitation flow have primarily focused a standing water environment, neglecting the impact of periodic disturbance in marine environment. Therefore, series functions with different frequencies and amplitudes are defined to simulate disturbance, slender projectile is adopted numerically study effect phenomenon this paper. Research results show that cavity profile evolves periodically external field. At same time, as frequency amplitude increase, minimum shape...

Abstract The erosion mechanism and deformation characteristics of rhomboid-shaped particle impacting metal beam are studied. Physical experiments cantilever fixed-fixed carried out respectively. behavior particles captured by high-speed imaging system. Meanwhile, the numerical models beam, based on FEM-SPH coupled method, established. effects geometrical parameters incident conditions impact position elastic-plastic rebound further analyzed. results show: (1) width affects its maximum...

In this paper, a recompiled multiphase flow solver, which introduced the lateral source into code, is developed to investigate effect of on supercavitation phenomenon. The evolution supercavity profile and resistance vehicle under different speeds are studied. results show that solver can calculate supercavitation, influence related speed counter flow. Under same velocity, higher convection weaker cavity resistance. When velocity less than 8% size be ignored. As strengthens, will deform even...

We conducted an experimental study on the formation of cavity and splash crown during impact superhydrophobic hydrophilic spheres water polyethylene oxide solution (non-Newtonian liquid). investigated influences falling speed formation. In particular, we focused evolution time when with different contact angles fall into liquids under various speeds behavior curtain. Results show that sphere angle liquid viscosity have a great effect The increase in induces However, has certain inhibitory...

Abstract An annular powder‐liquid mixer is a new type of jet pump used to mix powder. This mainly fracturing fluids in oil and natural gas exploitation processes. Free from powder pellets, the has characteristics, such as high mixing efficiency great suction. The structural parameters, hose diameter, exit section falloff angle, divergence length‐diameter ratio, nozzle may influence this mixer. By using an orthogonal experiment optimize structure ring‐type performing comparative analysis...

The separator is a key component of coal pneumatic conveying systems, which plays an important role in improving particle collection efficiency and reducing dust pollution. In this paper, combined rotary was designed. Based on the traditional cyclone separator, rotor blades were installed matched with guide vanes to increase material separation performance. influence speed characteristics studied by computational fluid dynamics simulation, flow field velocity pressure distribution trajectory...

In this paper, the super-cavitating phenomenon under effect of two vehicles’ encounter motion processes is numerically studied. Particular attention given to influence vertical gaps between vehicle, cavitation number, and slenderness ratio on cavity profile radial force object. Several numerical models are built study evolution process acting vehicle explore mechanism supercavitating flow. The shows that around primarily affected by but relatively weakly ratio. impact laws acquired in paper....

Fracturing operation is an important link in the process of petroleum and natural gas extraction, preparation fracturing fluid key factor to operation. In order solve problems insufficient amount rubber guanidine powder inhalation a lot package, new type dynamic mixer designed. The principle annular jet discrete action are applied design process. main advantages large intake, uniform mixing high efficiency. Through combination numerical simulation experimental verification, analyzed,...

In the paper, air cavity created by vertical water entry of cylinders with different slenderness ratio (defined as “s=L/D”) is investigated experimentally, theoretically, and computationally. The study focused on range Froude numbers, Fr = V /( gr ) 0.5, (12< Fr< 30). Particular attention given to effect ratios surface seal time, evolution process cavities. To understand physical processes, we conduct several experiments length cylinders. A theory model considering added mass (induced...

Abstract The distribution of abrasive particles in fluids is an important research topic the study waterjet cutting processes. However, it impossible to obtain accurate law and influencing factors by performing only experiments; therefore, necessary processes with help numerical models. existing models usually adopt form artificial settings for fluid. This method cannot accurately simulate random particles. In this paper, algorithm used impact azimuth water. smoothed particle hydrodynamics...