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.
Content and learning outcomes
Mathematical tools. The fundamental equations of fluid mechanics. The classical wave equation and its solutions. The inhomogeneous wave equation. Lighthills theory for aerodynamic sound. Curles equation. The convective wave equation. Sound propagation in ducts and pipes. Multi-port theory. Sound from moving sources. (”Ffowcs Williams&Hawkings equation”). Fluid driven self sustained oscillators – Whistles. Applications with focus on fluid machines and vehicles.
Laboratory exercise: Measurement of 2-port for a muffler.
Project assignment: Analysis of an exhaust muffler.
Intended learning outcomes
To present the fundamental theories for sound generation and propagation in fluids with non-stationary (turbulent) flow fields.
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.
Literature and preparations
Basic courses in mathematics, mechanics.
English B / English 6
Examination and completion
If the course is discontinued, students may request to be examined during the following two academic years.
- LAB1 - Exercises, 1.0 credits, grading scale: P, F
- LAB2 - Project, 1.0 credits, grading scale: P, F
- TEN1 - Examination, 2.0 credits, grading scale: A, B, C, D, E, FX, F
- ÖVN1 - Assignments, 2.0 credits, grading scale: P, 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
Written examination (TEN1; 2 university credits), approved exercises (ÖVN1; 2 university credits) approved measurement exercises (LAB1; 1 cr) and project work (LAB2; 1 university credits).
Opportunity to complete the requirements via supplementary examination
Opportunity to raise an approved grade via renewed examination
- 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 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 SD2155
Main field of study
SD2165 Acoustical Measurements
SD2150 Experimental Structure Dynamics
SD2175 Numerical Methods for Acoustics and Vibration
SD2180 Non-Linear Acoustics
SD2190 Vehicle Acoustics and Vibration