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FSD3120 Flow Acoustics I 6.0 credits

Course offerings are missing for current or upcoming semesters.
Headings with content from the Course syllabus FSD3120 (Autumn 2018–) are denoted with an asterisk ( )

Content and learning outcomes

Course contents

Mathematical tools. The fundamental equations of fluid mechanics. The classical wave equation and its solutions. Multi-port theory. The inhomogeneous wave equation. Lighthills theory for aerodynamic sound. Curles equation. The convective wave equation. Sound propagation in ducts and pipes. Sound from moving sources. (”Ffowcs Williams&Hawkings equation”). Fluid driven self sustained oscillators – Whistles. Applications with focus on fluid machines and vehicles.

Intended learning outcomes

Students graduating from the course should:

  • Be able to derive the classical wave equation and be familiar with the solutions under plane and spherical symmetry including Greens functions.

  • Be able to explain and apply a multipole-expansion and know the character of the simplest point sources (monopole, dipole, quadrupole).

  • Know about Lighthills acoustic analogy and its limitations and be able to explain the physical mechanisms that generate sound in a flow.

  • Know how flow and motion affects sound propagation and generation and be able to explain phenomena such as the Doppler-shift and the Mach-cone.

  • Be able to apply Lighthills analogy to fluid machines and vehicles and know how the different mechanisms scale with the flow speed.

  • Be able to explain how fluid driven self-sustained oscillators (”whistles”) are created and how they can be eliminated.

  • Be able to apply 2-port theory to analyse sound propagation in pipe and duct systems in particular with application to vehicle exhaust systems.

  • Have obtained training in experimental techniques for analysis of sound in ducts.

Course disposition

No information inserted

Literature and preparations

Specific prerequisites

SD1120 Noise and Vibration or equivalent.

Recommended prerequisites

SD1120 Noise and Vibration or equivalent


No information inserted


Compendium - An introduction to flow acoustics, Mats Åbom

Examination and completion

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

Grading scale

P, F


  • PRO1 - Project work, 4.0 credits, grading scale: G
  • TEN1 - Exam, 2.0 credits, grading scale: G

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.

Written examination + Home assignments + Project

Opportunity to complete the requirements via supplementary examination

No information inserted

Opportunity to raise an approved grade via renewed examination

No information inserted


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 FSD3120

Offered by

Main field of study

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

Education cycle

Third cycle

Add-on studies

No information inserted


Mats E G Åbom (

Postgraduate course

Postgraduate courses at SCI/Aeronautical and Vehicle Engineering