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

• Main Authors: , STEFANI BERTANIA MOTTO, , Dr. Adhika Widyaparaga, ST.
• Format: Theses and Dissertations NonPeerReviewed
• Published: [Yogyakarta] : Universitas Gadjah Mada 2014
• Subjects: ETD
• Online Access: https://repository.ugm.ac.id/129686/; http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=70082
• Institution: Universitas Gadjah Mada

Thermoaccoustic is one of cooling systems that environmentally friendly because it uses air or noble gas as the medium moves and works without moving parts like other coolers that require a compressor or fan. To pump heat out of system, thermoaccoustic cooling need sound waves from source that propagated through the tube which capable to resonance that waves. The waves then passed on a narrow slit which has a lot of cross-section (regenerator) that used as heat changer from working fluid to others. This process will create hot side and cool side in the regenator. In coaxial thermoaccoustic, hot side and cool side can exchange position by changing tool dimention and working frequency. This research uses travelling waves that comes from two wave source (speaker). Phase difference of two wave sources are described based on the position and travel time using two sensors method. This phase difference is used to examine thermoaccoustic effect changes, like direction of heat pumping that occurs in resonator tube. The experimental using working frequency of 260 Hz, 23 Watt input power and phase difference of 0 ° - 330 ° with a range of 30 ° to each test. Two sensors method are used to find the value of the acoustic intensity of the sound waves by placing two pressure sensors on the left and right side of the regenerator. This sensors are used to measure the pressure in the coaxial tube resonator. Five temperature sensors also placed along the regenerator to measure temperature distribution caused by heat pumping. To simplify calculation, results of pressure data then processed by using computer program Ms. Axcel and Matlab r2010A so we get accoustic intensity for each different phase of positive and negative value depending on the direction of propagation in the resonator. Then temperature distributin data in the regenerator taken from thermokopel sensor and recorded by computer program datalog.exe. From this research, it appears that change of acoustic intensity due to phase difference of two sound sources form a U-shaped graph with a peak at 180° phase difference. Change of accoustic intensity will affect the heat pumping in the regenerator, where in phase different 0°-150° heat pumping has opposite direction of acoustic intensity flow. In phase different 180°-330°, heat pumping has same direction of acoustic intensity flow. Temperature distribustion in regenerator also form U-shaped that indicates heat pumped into the banks of the regenerator.