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SG2221 Wave Motions and Hydrodynamic Stability 7.5 credits

The course is optional from all engineering programmes and is addressed to graduate and undergraduate students with fundamental knowledge and interest in fluid dynamics.

The course is specially recommended to students following the Master of Science in Engineering Mechanics programme.

Choose semester and course offering

Choose semester and course offering to see current information and more about the course, such as course syllabus, study period, and application information.

Headings with content from the Course syllabus SG2221 (Spring 2022–) are denoted with an asterisk ( )

Content and learning outcomes

Course contents

The student will acquire knowledge in fundamental concepts and phenomena in wave motions in fluids and in hydrodynamic instabilities. It will help you to understand the theory underlying some commonly observed flow phenomena, such as

  • why the surface waves behind a boat have a limited spreading angle
  • why the wake of a cylinder beats at a fixed frequency independently of the external disturbances
  • why Tsunamis arise and how they behave when approaching the shore
  • why the so spectacular Billow clouds in the atmosphere are formed

Intended learning outcomes

After completing this course the student should manage to:

  • describe the behaviour of surface gravity waves
  • explain the concept of group velocity of a wave
  • describe the main features of internal waves in continuously stratified fluids, such as in oceans and in the atmosphere
  • discuss the non-linear behaviour of water waves
  • identify the mechanisms behind instabilities in flows governed by thermal convection and heat exchange
  • discuss effects of centrifugal and Coriolis forces in unstable rotating systems
  • describe the instability nature and mechanisms in shear flows, i.e. wake, jet, boundary layer and channel flows
  • discuss the influence of viscosity on stability
  • explain why classic asymptotic stability analysis provides only a partial description of disturbance amplification in shear flows

Course disposition

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Literature and preparations

Specific prerequisites

To follow the course students (including master students) are required to have taken a course in fluid mechanics.
Compulsory courses of the main programmes at F or T. For F-students SG2223, for T-students SG1217 and for M- and P-students SG1220 are recommended. For M- and P-students 5B1304 is compulsory.

English B / English 6

Recommended prerequisites

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Examination and completion

If the course is discontinued, students may request to be examined during the following two academic years.

Grading scale

A, B, C, D, E, FX, F


  • INL1 - Calculation, 1.5 credits, grading scale: P, F
  • LAB1 - Experiment, 1.5 credits, grading scale: P, F
  • TEN1 - Examination, 4.5 credits, grading scale: A, B, C, D, E, FX, F

Based on recommendation from KTH’s coordinator for disabilities, the examiner will decide how to adapt an examination for students with documented disability.

The examiner may apply another examination format when re-examining individual students.

Other requirements for final grade

Combined oral and written examination (TEN1; 4,5 university credits)
Theoretical home assignment (INL1; 1,5 university credits)
Experimental wind tunnel lab (LAB1; 1,5 university credits)

Opportunity to complete the requirements via supplementary examination

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Opportunity to raise an approved grade via renewed examination

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Ethical approach

  • All members of a group are responsible for the group's work.
  • In any assessment, every student shall honestly disclose any help received and sources used.
  • In an oral assessment, every student shall be able to present and answer questions about the entire assignment and solution.

Further information

Course web

Further information about the course can be found on the Course web at the link below. Information on the Course web will later be moved to this site.

Course web SG2221

Offered by

Main field of study

This course does not belong to any Main field of study.

Education cycle

Second cycle

Add-on studies

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Outi Tammisola (, Luca Brandt (