Optimum Design of a Two Step Planar Diffuser: A Hybrid Approach

Abstract

This study attempts to optimize a planar diffuser with two steps using a hybrid approach. It uses CFD softwares: Gambit for mesh generation, Fluent for carrying out hydrodynamic analysis, and employs a Genetic Algorithm (GA) for optimization. Here, the GA and CFD softwares combine each other seamlessly and exchange data among the commercial softwares (namely Gambit and Fluent) and optimization tool (that is, GA) in a fully automated manner without any human intervention. The hydrodynamic analysis is used to calculate pressure drop across the diffuser for a fully turbulent flow, while the GA determines its optimum design, which minimizes the same. The optimum dimensions of the diffuser wall have been determined for different values of Reynolds number and area ratios between the outlet and inlet of the diffuser. Finally, relationships of optimum geometrical dimensions with the Reynolds number and area ratio have been developed for the ready use of designers.

Numerical modeling of converging compound channel flow

“…Mean Squared Error, Ep for pattern is defined as Ep = (11) Where Dpi is the target output, Opi is the computed output for the i th pattern.…”

“…Pan Speziale et al (1991) and Reynolds Stress or SMC-(implemented in ANSYS-CFX) models to trapezoidal channel. Thomas and Williams (1995a) and Cater and Williams (2008) In the last decade machine-learning methods were the subject of many researches in engineering problems and also in water resources engineering (Cheng et al, 2002;Lin et al, 2006;Muzzammil, 2008;Wang et al, 2009;Wu et al 2009;Ghosh et al, 2010;Safikhani et al, 2011). Bilgil and Altun (2008) In the first part of this paper, 3D numerical simulations of flow field with two phases (water & air) are carried out with the software ANSYS FLUENT to study the variation of velocity profiles in different converging sections of a compound channel.…”

Volumetric Three-Component Measurements of Air Jet Flows of Different Diffuser Designs

“…Designs of diffusers depend on the internal flow applications. Typical designs include twodimensional rectangular 10 , conical 11 , annular 12 , and radical-(an S duct with rectangular entrance and circular exit) in shape 9 .…”

Assessment Study of K-ɛ Turbulence Models and Near-Wall Modeling for Steady State Swirling Flow Analysis in Draft Tube UsingFluent

“…Design engineers must adapt new components to site operating conditions, but also to existing components for which replacement is not economically justifiable. Nowadays, such highly constrained design problems are often addressed through a recourse to automated design approaches and optimization methodologies (Ghosh et al, 2010). Optimal design approaches, however, come with their own set of challenges, as they rely on accurate evaluations of a cost function to efficiently explore complex design spaces.…”