Simulations of Cavitating Flows Using Hybrid Unstructured Meshes

Abstract

A new multi-phase model for low speed gas/liquid mixtures is presented; it does not require ad-hoc closure models for the variation of mixture density with pressure and yields thermodynamically correct acoustic propagation for multi-phase mixtures. The solution procedure has an interface-capturing scheme that incorporates an additional scalar transport equation for the gas void fraction. Cavitation is modeled via a finite rate source term that initiates phase change when liquid pressure drops below its saturation value. The numerical procedure has been implemented within a multi-element unstructured framework CRUNCH that permits the grid to be locally refined in the interface region. The solution technique incorporates a parallel, domain decomposition strategy for efficient 3D computations. Detailed results are presented for sheet cavitation over a cylindrical head form and a NACA 66 hydrofoil.

Numerical Analysis of Cavitating Flow Past Cylinder With Three Different Cavitation Models

“…하지만, 이 방법은 응축 증기와 비응축 증기를 구별할 수 없 는 단점이 있다. 두 번째 방법은 액상과 기상에 대해서 연속 방정식을 분리하여 해석하는 방법인데 액상과 기상 사이에 질량전달 소스항을 추가하는 방법으로 균일 혼상류 (homogeneous mixture)모델이라고 보통 일컫는다 [3,4,5,6]. 이 방법은 액상과 기상의 경계면의 상태가 열과 동적으로 평형 을 이루고 있다고 가정하므로 운동량 방정식과 에너지 방정 식은 혼상류(mixture flow)에 대한 방정식을 이용한다.…”

Numerical simulation of unsteady three-dimensional sheet cavitation

“…In 2D we will use lower-case symbols, i.e. 9) with C the closed curve of the object. For two-dimensional flow about a 2D geometry the lift force ℓ per unit length in span-wise direction is equal to the component of f in the direction normal to the free-stream, which in our case is f y .…”

Review of numerical models of cavitating flows with the use of the homogeneous approach

“…Many researches tried to identify the weak points of the Kubota model and suggested their own solutions of the pointed problems. Merkle et al [15][16][17] presented in 1998 their own version of source termṡ…”