JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Prerequisites

Thermodynamics 1 & 2

Course Objectives

The course is intended to

• Understand the fundamental concepts of turbo machines
• Apply concepts of fluid mechanics in turbo machines.
• Understand the thermodynamic analysis of steam nozzles and turbines.
• Understand the different types of compressors and evaluating their performances in the form of velocity triangles.
• Familiarize the basic concepts of gas dynamics and analyze the performance of axial flow gas turbines

Course Outcomes

At the end of the course, the student will be able to:

• To design and analyze the performance of Turbo machines for engineering applications
• To understand the energy transfer process in Turbo machines and governing equations of various forms.
• To understand the structural and functional aspects of major components of Turbo machines.
• To design various Turbo machines for power plant and aircraft applications
• Understand the design principles of the turbo machines
• Analyze the turbo machines to improve and optimize their performance

UNIT - I

Introduction and Origin Of Turbulence: Properties of laminar flow, Properties of turbulent flow. Boundary Layer: Boundary Layer, Growth rate of Boundary layer for Laminar and Turbulent Flows. Characteristics of Turbulent Flow: The Origin of Turbulence, Nature of Turbulence, Swirling Structure, Mean Motion and Fluctuations, Consequences of Turbulence, Homogeneous Isotropic Turbulence. Correlation Functions, Kolmogorov Hypothesis and Probability Density Function: Correlation Functions, Ideas about eddy size, Intensity of Turbulence or Degree of Turbulence. Kolmogorov Hypothesis and Energy Cascade: Kolmogorov Universal Law for the Fine Structure, Energy Cascade, Kolmogorov Length Scale, Kolmogorov's First Hypothesis, Kolmogorov's Second Hypothesis. Probability Density Functions and Averaging: Introduction, Probability density function, averaging used in the analysis of turbulent flows.

UNIT - II

Reynolds Averaged Navier-Stokes Equations and Classical Idealization Of Turbulent Flows: Reynolds' Decomposition, Examples of Turbulent Fluctuations, some Measurements on Fluctuating Components. Measurements on Fluctuating Components: Shear Stress due to the Fluctuations, The boundary layer measurements of Klebanoff. Turbulent Boundary Layer Equations: Turbulent Boundary Layer Equations for a two-dimensional flow. Classical Idealization of Turbulent Stresses: Introduction, The boussines or eddy viscosity model, Eddy viscosity.

UNIT - III

Vorticity Dynamics: Introduction, Vorticity and the equations of motion, Reynolds stress and vorticity. Vortex Stretching. The Vorticity Equation, Vorticity in Turbulent Flows. Dynamics of Turbulent Kinetic Energy and Important Scaling Relations: Kinetic Energy of the Mean Flow. Kinetic Energy of Fluctuations. Scaling Relations.

R19 M.Tech. Thermal Engineering

UNIT - IV

Wall Bounded Flows and Free Shear Flows: The Law of the Wall for Wall Bounded Flows, The Universal Velocity Profile. Free Shear Flows, Turbulent Jets, Uniform Eddy Viscosity model. Spectral Dynamics: Correlation Functions and Spectra. Correlation Functions and Spectra. Large - Eddy Simulation of Turbulent Flows: RANS Equations and Eddy Viscosity: Introduction Reynolds Averaged Navier-Stokes (RANS) Equations, Eddy Viscosity Models, Zero-Equation Models. One-Equation Model: One-Equation Model, Two-Equation Model. Two Equation Models: k - ω Model, SST (Shear Stress Transport) Turbulence Model. Discussion on Applicability

UNIT - V

Large - Eddy Simulation of Turbulent Flows: Low Reynolds number k - ε model: Special Features of Near Wall Flow, Near Wall Treatment in Transport Equation based Models, Wall Function Approach, Low Reynolds number version of k - ε model: Asymptotic Consistency, Damping Functions. RNG k - ε Model and Kato-Launder Model. The Realizable k - ε Model, Reynolds Stress Models (RSM), Large Eddy Simulation (LES). Mathematical Modeling of Turbulent Flows: The Filtered Navier- Stokes Equations, Subgrid Scale Closure, Standard Subgrid-Scale Model. Dynamic Model of LES. Direct Numerical Simulation.

TEXT BOOKS:

• 1. A First Course in Turbulence by H. Tennekes and J.L. Lumley, 1987, The MIT Press, Cambridge, Massachusetts, and London, England.
• 2. Fluid Mechanics by P.K. Kundu and I.M. Cohen, 2002, Academic Press (An Imprint of Elsevier Science, USA.

REFERENCE BOOKS:

• 1. Turbulent Flows by S.B. Pope, 2000, Cambridge University Press, UK.
• 2. Turbulent Flows: Fundamentals, Experiments and Modeling by G. Biswas and V. Eswaran, 2002, Narosa Publishing House, New Delhi, India. R19 M.Tech. Thermal Engineering M. TECH. I Year I Sem. (THERMAL ENGINEERING)