CFD In nuclear applications презентация

Александр Александрович

CFD IN NUCLEAR APPLICATIONS

ИЯЭ и ТФ
Кафедра «ЯР и ЭУ»

2017 г.

Trees and plants must bend!!!”

Leorando da Vinci (1452-1519)

(LES)
Detached Eddy Simulations (DES) (Philippe Spalart)

Spectral Method

shock
Counter-current flow in cold and hot legs;
Flows in tee junctions;
Containment flow in LOCA
Natural circulations;
Liquid / gas stratification;
Bubble dynamics

CFD IN NUCLEAR
APPLICATIONS

with a subject of my master thesis. A subject of my master's thesis is modeling the processes of mixing non-isothermal flows. I conduct experiments on mixing non-isothermal flows now, and I am going to visualize these flows in the CFD programs then. The main objective of this article is to present a need and the importance of Computational Fluid Dynamics (CFD) simulation for the complex natural circulation phenomena in water cooled nuclear plant components.
The Computational Fluid Dynamics (CFD) is one of the branches of fluid mechanics that uses numerical methods and algorithms to solve and analyze problems that involve fluid flows. Accurate CFD computer programs that can simulate complex scenarios such as turbulent flows are an ongoing challenging area of research. The principal interest of computational fluid dynamics (CFD) in nuclear applications is mainly in the capability to obtain at a lower cost, valuable information on some physical phenomena.
The governing processes occurring in water reactors are without exception related to complex multiphase flows. Because of the large scales, inaccessibility and hostile high thermal conditions in and the reactor components, it is extremely difficult to obtain very detailed on line information of theses processes.
The fundamental basis of any CFD problem is the Navier-Stokes equations, which define any single-phase fluid flows.
Nature is characterized by three dimensional flows and turbulence plays a predominant part in the in the development of these flows. Turbulence flows have properties that make it difficult to develop an accurate tractable theory.
The article describes the different ways to solve The Navier-Stokes equations (NSE) and ways to describe turbulent flow (LES, RANS, RSM, DES).
Examples of CFD simulations of natural circulations are given. However, confidence in the CFD calculations should be assessed. Verification and validation (V&V) are the major processes for assessing and quantifying this confidence. A brief review of V&V terminology and approaches will be discussed.