Course content

Phenomenological and theoretical introduction to turbulence, microscales and integral scales. Reynolds' decomposition and Reynolds' averaging. Homogeneous turbulence. Turbulent shear flows: boundary layers, pipe flows and jets. Engineering calculation approaches: integral methods, mean field methods, and large-eddy simulations. Turbulens modelling: algebraic and transport models. Examples of numerical solutions of internal and external flows.

Learning outcome

Knowledge:
After completion of this course, the student will have knowledge on:
- Basic laws in fluid mechanics. Cartesian tensor notation.
- Dimensionless equations. Reynolds and Strouhal number, scales for length and time.
- Vorticity and elements of vortex dynamics.
- Characteristics of turbulence. Kolmogorov’s micro scales.
- Reynolds’ decomposition, Reynolds-averaged Navier-Stokes equation (RANS).
- Balance equations for the mean flow and the turbulent kinetic energy.
- Turbulence near solid surfaces. The mean velocity profile. Boundary layer equations.
- Free turbulent shear flows. Simplified momentum equations. Self-preservation.
- Turbulence modelling. Eddy viscosity, mixing-length, Reynolds stress models.
- Statistical description of turbulence: moments, correlations, spectra.
- Direct numerical simulation (DNS) and large-eddy simulation (LES).

Skills:
After completion of this course, the student will have skills on:
- Evaluation of turbulent flow situations.
- Use of self-preservation solutions for free shear flows (jets, wakes etc).
- Choose a turbulence model for computational flow analysis (CFD).
- Evaluate and interpret results from CFD.
- Evaluate and interpret experimental measurements.

General competence:
After completion of this course, the student will have general competence on:
- The theory of turbulence and the turbulent flow of liquids and gases (fluids).
- An understanding of turbulent flow cases.

Learning methods and activities

Lectures and written exercises. The lectures and exercises are in English when students who do not speak Norwegian take the course. At postponed exam (re-sit examination), a written exam may be changed to an oral exam.

Compulsory assignments

• Exercises

Recommended previous knowledge

Priot knowledge about the Navier-Stokes equations, for instance from the course "Viscous flows and boundary layers".

Course materials

Parts if different literature together with parts from F.M. White: "Viscous Fluid Flow", 4th edition, McGrawHill.