Доступ предоставлен для: Guest
TSFP DL Home Архив Исполнительный Комитет

MODELLING THE EFFECT OF ACTIVE FLOW CONTROL VIA PULSATION ON TURBULENT FLOW IN A 10° PLANE DIFFUSER

Timothy J. Craft
Turbulence Mechanics Group, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, PO Box 88, Manchester M13 9PL, UK

Hector Iacovides
Turbulence Mechanics Group, School of Mechanical, Aerospace and Civil Engineering. The University of Manchester, Manchester M13 9PL, U.K.

Parham Momeni
School of Mechanical, Aerospace and Civil Engineering, The University of Manchester M60 1QD, United Kingdom

Аннотация

In recent years there has been considerable interest in the active control of fluid flow phenomena. Applications include separation control, drag reduction and lift enhancement. The present study is concerned with flow separation and reattachment, and considers the case of flow through a 10° plane diffuser, studied experimentally by Masuda et al (1994), where the control is provided by a periodic injection/suction upstream of where the flow would separate under stationary conditions.
Results are reported using the two-equation linear k−ε model of Launder & Sharma (1974) and a two-equation non-linear k−ε scheme (Craft et al., 2005), in conjunction with the Reynolds-averaged momentum (URANS) equations. The linear scheme does not capture the flow separation in the unforced case, whilst the non-linear model does better, although slightly underpredicts the recirculation zone size. In the unsteady, forced, cases the non-linear scheme generally reproduces the effect of the forcing in enhancing the coherence of the separated shear layers and reducing the reattachment length at the lower forcing frequencies, whilst showing a smaller effect as the frequency is increased.