COBEM99

SR13 Mecânica dos Fluidos

Title:

A FORMULATION OF LAW OF THE WALL FOR TURBULENT FLOW WITH SEPARATION AND HEAT TRANSFER.

Summary :

ABSTRACT. THE DESCRIPTION AND ANALYSIS OF THE TURBULENT FLOW CLOSE TO THE SEPARATION POINT AND IN THE RECIRCULATION REGION IT IS AN IMPORTANT PROBLEM OF GREAT COMPLEXITY. ONE OF THE MAIN DIFFICULTIES IS THE FACT THAT THE CHARACTERISTIC VELOCITY USED IN THE OBTAINING OF THE ASYMPTOTIC STRUCTURE FAR AWAY FROM THE REATTACHMENT POINT, LOSES IT’S VALIDITY IN THIS REGION DUE TO THE DISAPPEARANCE OF THE SHEAR STRESS AT THE WALL. THIS WORK PRESENTS AN ALTERNATIVE LENGTH SCALE FOR THE DESCRIPTION OF THE VELOCITY PROFILE VALID FOR BOTH ATTACHMENT AND REATTACHMENT REGIONS. BESIDES, TWO LAWS OF THE WALL, RECENTLY PROPOSED FOR THE PROFILES OF SPEED AND TEMPERATURE, DEVELOPED FOR THE SEPARATION REGION, ARE APPLIED TO THE TREATMENT OF THE NEAR WALL REGION IN THE TURBULENCE K-EPSILON MODEL. THE GOVERNING EQUATIONS ARE REWRITING APPLYING THE FINITE VOLUMES APPROACH COUPLED TO A HYBRID SCHEME FOR THE SIMULTANEOUS TREATMENT OF THE CONVECTIVE AND DIFUSIVE TERMS. THE GROUP OF THE EQUATIONS OF FINITE DIFFERENCES IS SOLVED THROUGH THE NUMERIC CODE TEACH-2E. THE RESULTS ARE COMPARED WITH EXPERIMENTAL DATA SHOWING GOOD AGREEMENT. KEY-WORDS: TURBULENCE, K-EPSILON MODEL, LAW OF THE WALL, TEMPERATURE

Author :

Batista, Fabio Nogueira
Bortolus, Marcos Vinicius
Cruz, Daniel Onofre de Almeida
Guerra, Danielle Regina

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