search query: @instructor Penttinen, Henri / total: 6
reference: 2 / 6
« previous | next »
Author:Tahvanainen, Henna
Title:Modelling body vibration and sound radiation of a modified kantele
Muunnellun kanteleen kopan värähtelyn ja äänisäteilyn mallintaminen
Publication type:Master's thesis
Publication year:2012
Pages:viii + 55 s. + liitt. 10      Language:   eng
Department/School:Signaalinkäsittelyn ja akustiikan laitos
Main subject:Akustiikka ja äänenkäsittelytekniikka   (S-89)
Supervisor:Välimäki, Vesa
Instructor:Penttinen, Henri
Electronic version URL: http://urn.fi/URN:NBN:fi:aalto-201302031390
OEVS:
Electronic archive copy is available via Aalto Thesis Database.
Instructions

Reading digital theses in the closed network of the Aalto University Harald Herlin Learning Centre

In the closed network of Learning Centre you can read digital and digitized theses not available in the open network.

The Learning Centre contact details and opening hours: https://learningcentre.aalto.fi/en/harald-herlin-learning-centre/

You can read theses on the Learning Centre customer computers, which are available on all floors.

Logging on to the customer computers

  • Aalto University staff members log on to the customer computer using the Aalto username and password.
  • Other customers log on using a shared username and password.

Opening a thesis

  • On the desktop of the customer computers, you will find an icon titled:

    Aalto Thesis Database

  • Click on the icon to search for and open the thesis you are looking for from Aaltodoc database. You can find the thesis file by clicking the link on the OEV or OEVS field.

Reading the thesis

  • You can either print the thesis or read it on the customer computer screen.
  • You cannot save the thesis file on a flash drive or email it.
  • You cannot copy text or images from the file.
  • You cannot edit the file.

Printing the thesis

  • You can print the thesis for your personal study or research use.
  • Aalto University students and staff members may print black-and-white prints on the PrintingPoint devices when using the computer with personal Aalto username and password. Color printing is possible using the printer u90203-psc3, which is located near the customer service. Color printing is subject to a charge to Aalto University students and staff members.
  • Other customers can use the printer u90203-psc3. All printing is subject to a charge to non-University members.
Location:P1 Ark Aalto  1497   | Archive
Keywords:acoustics
music
finite element methods
vibrations
akustiikka
musiikki
elementtimenetelmät
värähtelyt
Abstract (eng): In this thesis, the vibrational modes and radiation of the body of a 15-string instrument called the kantele are modeled using the finite element method.

Two traditional body structures, the top-plate kantele and the box kantele, are compared to a modified kantele with an air gap separating the top and the back plate.
The modified structure allows the kantele top plate to vibrate freely.
In addition, together the top and back plate create an enclosed air mass that has its own vibrational modes.
The modified kantele has previously been shown to be louder than the traditional top plate kantele.

In this thesis, it is shown that the modified kantele includes vibrational modes of both the freely vibrating top plate and the enclosed air.
Thus, it has a higher mode density than the traditional kanteles.
Because of the coupling of the enclosed air modes to the body, the modified kantele radiates more omni-directionally than the traditional kanteles.
Consequently, the modified kantele has a higher radiation efficiency than the traditional kanteles when the size of the air gap is small (1-3 mm).
Abstract (fin): Tässä työssä mallinnetaan 15-kielisen kanteleen kopan värähtelyä ja säteilyä elementtimenetelmän avulla.
Kahta perinteistä kopan rakennetta, laatikkokanteletta ja lautakanteletta, verrataan muunneltuun rakenteeseen, jossa kopan ja kannen välillä on ilmarako.
Tämä rakenne, jota kutsutaan myös nimellä vapaareuna-erillispohjarakenne, mahdollistaa kannen vapaan värähtelyn.
Lisäksi pohjan ja kannen sulkemalla ilmatilalla on omat värähtelymuotonsa.
Tämä muunnellun kanteleen on osoitettu olevan äänekkäämpi kuin perinteiset kanteleet.

Tässä työssä osoitetaan, että muunnellussa kanteleessa yhdistyvät sekä kannen että ilmatilan värähtelymuodot.
Siksi muunnellulla kanteleella on suurempi värähtelymuototiheys kuin perinteisillä kanteleilla.
Muunneltu kantele on myös ympärisäteilevämpi, sillä ilmatilan värähtelymuodot kytkeytyvät kopan värähtelyihin.
Tästä seuraa, että muunnellun kanteleen säteilytehokkuus on suurempi, kun ilmarako on pieni (1-3 mm).
ED:2013-01-14
INSSI record number: 45807
+ add basket
« previous | next »
INSSI