COBEM99

S15 Métodos Híbridos em Engenharia Mecânica

Title:

A TURBULENCE MODEL FOR NON-NEWTONIAN POWER-LAW FLUIDS IN DUCTS

Summary :

ABSTRACT. THE PROBLEM OF THE TURBULENCE MODELING FOR NON-NEWTONIAN POWER-LAW FLUIDS INSIDE DUCTS APPEARS IN MANY FIELDS OF CHEMICAL, FOOD AND MECHANICAL ENGINEERING. IN SPITE ITS IMPORTANCE, VERY FEW ARTICLES CAN BE FOUND IN THE LITERATURE THAT ANALYZE THE CHARACTERISTICS OF THE TURBULENCE PHENOMENON FOR NON-NEWTONIAN POWER-LAW FLUIDS. IN THIS CONTEXT, THE PURPOSE OF THIS WORK IS TO ANALYZE THE PROBLEM OF THE TURBULENCE MODELING OF SUCH FLUIDS. FIRST, THE KOLMOGOROV CHARACTERISTIC PARAMETERS FOR THE CASE OF POWER-LAW FLUIDS IS OBTAINED. THE CHARACTERISTIC DISSIPATION LENGTH, IS SHOWED TO BE A FUNCTION OF THE POWER-LAW INDEX (N) AND REDUCES TO THE NEWTONIAN CASE WHEN N = 1. IN PARALLEL, A TURBULENCE ALGEBRAIC MODEL IS PROPOSED, IN WHICH AN EXTENSION OF THE VAN-DRIEST DAMPING FUNCTION FOR THE POWER-LAW FLUIDS IS DEVELOPED. A NUMERICAL SOLUTION FOR THE HYDRODYNAMICALLY DEVELOPED TURBULENT EQUATION OF MOTION FLOW IN DUCTS IS OBTAINED. A COMPARISON WITH EXPERIMENTAL DATA AND AN EMPIRICAL CORRELATION FOR TURBULENT FLOW OF NON-NEWTONIAN POWER-LAW FLUIDS IS MADE, SHOWING GOOD AGREEMENT. KEYWORDS: TURBULENCE MODEL, POWER-LAW FLUIDS, PIPE FLOW.

Author :

CRUZ, DANIEL ONOFRE DE ALMEIDA
MACÊDO, EMANUEL NEGRÃO
MANESCCHY, CARLOS EDILSON
QUARESMA, JOÃO NAZARENO NONATO

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