PERUBAHAN EFEK TERMOAKUSTIK PADA RESONATOR DENGAN DRIVER AKUSTIK GANDA AKIBAT VARIASI MAGNITUDE

• Main Authors: , HENDRA PRASETYA BASKORO AJIE, , Dr. Adhika Widyaparaga, S.T. M.Biomed.Sc.
• Format: Theses and Dissertations NonPeerReviewed
• Published: [Yogyakarta] : Universitas Gadjah Mada 2014
• Subjects: ETD
• Online Access: https://repository.ugm.ac.id/131518/; http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=72014
• Institution: Universitas Gadjah Mada

Thermoacoustics is a field of study that is related to the physical phenomenon where a difference in temperature can produce sound waves. The medium used as the heat absorption system in thermoacoustic is air. In this medium, propagation of acoustic waves that is generated by the sound source occurs, so that it creates pressure, united oscillating movements and temperature oscillation. When acoustic waves propagate in a narrow canal, heat will also flow from and to the canal wall. Based on the equation for intensity of sound, it is known that intensity of sound is influenced by how big the the magnitude is and the phase difference. Referring to that, this research is done by varying the magnitude. Testing was done using a work frequency of 260 Hz, 0° phase, input power 23 Watt and �4 dBmagnitude on side A, while on side B the magnitude was varied�� dB, �30 dB, �17 dB, �13 dB, �11 dB, �9 dB,�7 dB until�4 dB. Two sensor method was used to find the value of acoustic intensity from the sound waves. Both of the pressure sensors were placed in the right and left side of the regenerator. This sensor was used to measure pressure that occurred in the resonator tube. Five temperature sensor was also placed along the regenerator to measure the heat distribution caused by the heat pump. Results from the pressure data retrieval was processed using computer programs Ms Excel and Matlab r2010A so acoustic intensity was obtained for every magnitude that had a positive and negative value depending on the direction of propagation on the resonator. Temperature distribution data on the regenerator was taken from the thermocouple sensor and recorded by computer program datalog.exe. From the research it can be seen that change in acoustic intensity is affected by change in magnitude. On side B, acoustic intensity increased when the magnitude was �� dB until �4 dB. Change in acoustic intensity will affect the heat pump in the regenerator. When the magnitude on side B was �� dB, �30 dB, �17 dB, �13 dB, �11 dB, �9 dB and �7 dB, the acoustic intensity on side A is relatively larger compared to the acoustic intensity on side B. This causes the direction of the heat pump to flow towards side B. So that the temperature in the regenerator on side B is higher compared to side A. When the magnitude on side B was �4 dB, the acoustic intensity on both sides were almost the same and resulted in temperature distribution that formed a U-shaped graph that indicates heat being pumped towards the ends of the regenerator. So that temperature in the middle of the regenerator was lower than the temperature on the ends of the regenerator.