In this paper, we construct various special solutions on a convergent-divergent surface for the steady compressible complete Euler system and established the stability of the purely subsonic flows. For a given pressure p0 prescribed at the “entry” of the surface, as the pressure p1 at the “exit” decreases, the flow patterns on the surface change continuously as those happen in a de Laval nozzle...

Hertzian dipole radiation from narrow circumferential slots on a conducting circular cylinder is studied. Eigenfunction expansions are used and boundary conditions are enforced to obtain a set of simultaneous equations. A fast convergent series formulation is obtained and numerical results are shown. Our theory provides a viable model for dipole radiation from a circumferential slot array on a ...

This paper investigates a clustering instability of a freely falling granular jet composed of 100 microm glass spheres. The granular flow out of a circular nozzle starts out spatially uniform and then, further downstream, breaks up into well-defined clusters. An optical method is used that measures inhomogeneities in the flow in order to quantify the growth of the clusters. The role of air is i...

Direct numerical simulation is used to study the effect of crossflow on the dynamics, entrainment and mixing characteristics of vortex rings issuing from a circular nozzle. Three distinct regimes exist, depending on the velocity ratio (ratio of the average nozzle exit velocity to free-stream crossflow velocity) and stroke ratio (ratio of stroke length to nozzle exit diameter). Coherent vortex r...

Sprinkler selection influences the water distribution uniformity of center pivot irrigation systems. The sprinkling uniformity of the center pivot is crucial for the yield and quality of crops on a large scale. Rotating and fixed spray plate sprinklers (RSPSs and FSPSs) are the two most popular types. However, sprinkler selection is mainly based on price, not on differences in performance betwe...

<p style="text-indent:20px;">This paper concerns continuous subsonic-sonic potential flows in a two dimensional convergent nozzle, which is governed by free boundary problem of quasilinear degenerate elliptic equation. It shown that for given nozzle perturbation an straight one, and mass flux, there exists uniquely flow whose velocity vector along the normal direction at inlet sonic curve...

By means of a transient transonic helium jet generated by a convergent-divergent conical nozzle, a unique biolistic method of accelerating microparticle formulations of DNA vaccines or drugs to penetrate the outer layer of human skin or mucosal tissue to elicit an physiological response for the treatment of a range of diseases. In this paper, Computational Fluid Dynamics is utilized to predict ...

The nozzle is a widely used device in daily life, such as water fountains to rocket engines. It important find out the influence of position throat for application or design nozzle. To that end, finite difference method was employed solve 1D Euler equations obtain flow inside implement method, an in-house python code developed. relationship among velocity, pressure and density convergent-diverg...