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Abstrak :
Alat pendingin adalah salah satu peralatan bantu yang sering digunakan. Fungsi utama dari a/at pendingin adalah menurunkan dan memelihara temperatur dari makanan atau benda lainnya pada temperatur yang lebih rendah dari temperatur lingkungan dengan tujuan untuk menjaga makanan dan benda lainnya pada kandisi yang baik dengan periode hidup yang lebih panjang. Termoakustik refrigerator adalah system pendinginan yang ramah lingkungan karena menggunakan media kerja udara atau gas mulia sebagai pengganti system Freon atau system kanvensional yang dapat membahayakan lingkungan. System ini berkerja dengan memanfaatkan gelombang suara yang dihasilkan oleh loudspeaker sebagai salah satu komponen system tersebut. Gelombang suara yang dihasilkan memberikan perpindahan panas dari tendon dingin menuju tendon panas melalui sebuah a/at pemindahan panas yang disebut dengan stack dimana diletakan di dalam pipa resonator. Dalam percobaan termoakustik ini, kami menguji sebuah a/at termoakustik sederhana dengan pipa resonator dengan terbuat dengan bahan PVC. Sebelumnya tealah dilakukan pengujian pada resonator dengan panjang 80 em dengan variasi posisi, panjang, dan model dari stack serta frekuensi yang digunakan, dengan tetap menggunakan udara atmosfer sebagai jluida kerja. Percobaan yang dilakukan saat ini ingin membandingkan karakterisasi termoakustik jika menggunakan a/at eksperimen yang lebih kecil dengan mengatur ulang ukuran dari parifang resonator dan panjang stack. Percobaan kali ini menggunakan tiga dimensi panjang resonator dan empat dimensi panjang stack sebagai variasi percobaan. Perpindahan panas dari tendon dingin ke tendon panas menghasilkan penurunan temperature sebesar 4°C pada tendon dingin dan kenaikan temperature pada tendon panas sebesar 2°C setelah dioperasikan selama 20 menit.

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Refrigerator is one of auxiliary device that is commonly used.The main function of refrigerator is decreasing and maintaining the temperature of foods and other goods in lower temperature than ambient in objective to keep foods and goods at good condition and longer period of life. Thermoaccoustic refrigerator is an environmental friendly cooling system because it uses air or noble gas as a working medium rather that freon or other hazardous gas as in conventional cooling system. This system utilizes sound wave to provide work for transferring heat from the cold to the hot reservoirs through an heat exchanger element called stack which is placed in a resonator tube. The sound source system consists of a loudspeaker, an audio ampilier, and a signal generator. In this experiment the main parts of the device consist of a cylindrical resonator made of PVC pipe , a loudspeaker as a sound source, and a stack as a heat transfer element. It has been done before by previous thermoacoustic research project that is used a 80cm length of PVC pipe and the variation in position, length and shape of stack and resonance frequency, using atmospheric air as a working medium. This working researh project want to compare the characterization of thermoacoustic in smaller dimension of researh apparatus by resizing the length of resonator and the length of the stack. The experiment had used three dimension of resonator length, four dimension of stack length, as a variation of the experiment. A heat transfer from cold reservoir to hot reservoir in each length of resonator and length of stack has been observed where the cold reservoir temperature decreased about 4°C and the hot reservoir temperature increased about 2°C after 20 minutes of the device operation

Abstrak :
Skripsi ini membahas mengenai sebuah fenomena dari suatu alat yang bernama thermoacoustic. Fenomena tersebut yaitu adanya aliran udara dalam suatu wadah yang dikompresi melalui suatu getaran yang berasal dari loudspeaker sehingga menyebabkan perbedaan temperatur. Pembahasan difokuskan pada tiga variasi material stack berupa sedotan yang berasal dari material jenis polypropylene, berupa film yang berasal dari material jenis mylar, dan berupa kardus yang berasal dari material jenis wood. Skripsi ini bertujuan untuk mengetahui perbandingan ketiga stack. Dari grafik hasil tersebut didapat perbedaan temperatur pada stack yang berasal dari sedotan sebesar 4,2°C. Pada stack yang berasal dari material mylar sebesar 5°C dan pada stack yang berasal dari kardus didapat perbedaan temperatur sebesar 3,9°C.

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This thesis is dealing with a phenomenon called thermoacoustic. The phenomenon is about a flow of air in a place that was compressed with a vibration from loudspeaker so that cause different temperature. Discussion focused on the three material variation of stack as a straw from polypropylene, as a fil from mylar material, as a box from wood material. The goal from this thesis is to know camparison of three stack. From graphic result had different temperature of stack from straw is 4,2°C. A stack from mylar material is 5°C and a stack from wood had different temperature about 3,9°C.

Abstrak :
Alat pendingin adalah salah satu peralatan rumah tangga yang sering kita gunakan, refrigerator sangat bermanfaat karena dapat membuat kondisi makanan yang kita simpan tetap bagus keadaannya, hal itu membuat alat pendingin sebagai salah satu peralatan rumah tangga yang sering kita jumpai. Termoakustik refrigerator adalah system pendinginan yang ramah lingkungan karena menggunakan media kerja udara atau gas mulia sebagai pengganti system Freon atau system pendinginan konvensional yang dapat membahayakan lingkungan. System ini berkerja dengan memanfaatkan gelombang suara yang dihasilkan oleh loudspeaker sebagai salah satu komponen system tersebut. Gelombang suara yang dihasilkan memberikan perpindahan panas dari tendon dingin menuju tendon panas melalui sebuah alat pemindahan panas yang disebut dengan stack dimana diletakan di dalam pipa resonator. Dalam pengujian, kami menguji sebuah alat termoakustik sederhana dengan pipa resonator dengan panjan 80cm terbuat dengan bahan PVC menggunakan pengaruh variasi posisi ,panjang dan model stack serta variasi frekuensi yang digunakan. Perpindahan panas dari tendon dingin ke tendon panas menghasilkan penurunan temperatur sebesar 6°C pada tendon dingin dan kenaikan temperatur pada tendon panas sebesar 3°C setelah dioperasikan selama 30 menit. ......Refrigerator is one of a household appliance that is commonly used. The needs of maintaining food at the good condition make refrigerator become 'must have' equipment in every household. Thermoaccoustic refrigerator is an environmentally friendly cooling system because it uses air or noble gas as a working medium rather that freon or other hazardous gas as in conventional cooling system. This system utilizes sound wave to provide work for transferring heat from the cold to the hot reservoirs through an heat exchanger element called as stack which is placed in a resonator tube. The sound source system consists of a loudspeaker, an audio ampilier, and a signal generator. In this experiment the main parts of the device consist of a cylindrical resonator made of PVC pipe has 80 cm length , a loudspeaker as a sound source, and a stack as a heat transfer element. The device was operated with variation position, length and shape of stack and also variation resonance frequency, using atmospheric air as a working medium. A heat transfer from cold reservoir to hot reservoir has been observed where the cold reservoir temperatur decreased about 6°C and the hot reservoir temperatur increased about 3°C after 30 minutes of the device operation.

Abstrak :
The fluid flow pattern in a thermoacoustic resonator is an important characteristic that affects the performance of the thermoacoustic refrigerator. The main factor that affects the flow and subsequently the heat transfer processes between the oscillating fluid and the stack walls is the geometry of the stack unit, especially related to the stack thickness and stack separation. In this paper, a two-dimensional numerical simulation of the inviscid fluid flow around the stack unit in a quarter wavelength resonator is carried out by using the continuity, Navier-Stokes, energy and ideal gas equations. These equations are solved using the perturbation method and the finite difference method. Three cases of different stack plate thickness are investigated: negligible, 0.4 mm and 0.8 mm thicknesses, respectively. The stack separation has also been varied for the 0.4 mm thickness, within and beyond that recommended by previous studies. Results show that vortices and streaming are always present, more significantly with the thicker plates. Concentrated vortices in the thick plate case stay longer than those with the thinner plate. They contribute to the high heat transfer rate as shown by the temperature profiles.

Abstrak :
Alat pendingin adalah salah satu peralatan rumah tangga yang sering kita gunakan, refrigerator sangat bermanfaat karena dapat membuat kondisi makanan yang kita simpan tetap bagus keadaannya, hal itu membuat alat pendingin sebagai salah satu peralatan rumah tangga yang sering kita jumpai. Termoakustik refrigerator adalah system pendinginan yang ramah lingkungan karena menggunakan media kerja udara atau gas mulia sebagai pengganti system Freon atau system pendinginan konvensional yang dapat membahayakan lingkungan. System ini berkerja dengan memanfaatkan gelombang suara yang dihasilkan oleh loudspeaker sebagai salah satu komponen system tersebut. Gelombang suara yang dihasilkan memberikan perpindahan panas dari tendon dingin menuju tendon panas melalui sebuah alat pemindahan panas yang disebut dengan stack dimana diletakan di dalam pipa resonator. Dalam pengujian, kami menguji sebuah alat termoakustik sederhana dengan pipa resonator dengan panjan 80cm terbuat dengan bahan PVC menggunakan pengaruh variasi posisi ,panjang dan model stack serta variasi frekuensi yang digunakan. Perpindahan panas dari tendon dingin ke tendon panas menghasilkan penurunan temperatur sebesar 6°C pada tendon dingin dan kenaikan temperatur pada tendon panas sebesar 3°C setelah dioperasikan selama 30 menit. ......Refrigerator is one of a household appliance that is commonly used. The needs of maintaining food at the good condition make refrigerator become 'must have' equipment in every household. Thermoaccoustic refrigerator is an environmentally friendly cooling system because it uses air or noble gas as a working medium rather that freon or other hazardous gas as in conventional cooling system. This system utilizes sound wave to provide work for transferring heat from the cold to the hot reservoirs through an heat exchanger element called as stack which is placed in a resonator tube. The sound source system consists of a loudspeaker, an audio ampilier, and a signal generator. In this experiment the main parts of the device consist of a cylindrical resonator made of PVC pipe has 80 cm length, a loudspeaker as a sound source, and a stack as a heat transfer element. The device was operated with variation position, length and shape of stack and also variation resonance frequency, using atmospheric air as a working medium. A heat transfer from cold reservoir to hot reservoir has been observed where the cold reservoir temperatur decreased about 6°C and the hot reservoir temperatur increased about 3°C after 30 minutes of the device operation.

Abstrak :
The Brundtland Report (also known as Our Common Future) has placed sustainability of energy resources and environmental degradation on a common global agenda. Increasing awareness has spurred much research into alternative clean energy technologies. Thermoacoustic cooling as an environmentally friendly refrigeration system is one of the research areas being pursued. Although not commercially available, successful systems have been completed. There are, however, still many fundamental issues related to the thermoacoustic effects and the associated heat transfer that must be addressed. This paper reports a portable counter-top thermoacoustic cooling apparatus designed and fabricated at the Universiti Teknologi Malaysia (UTM). Based on a standing wave resonator tube, the system with a pvc resonator tube of 60 mm diameter which was initially at 24o C, accomplished cooling effects under a minute, up to 18.5o C, without the use of chlrofluorocarbons (CFCs) or other similar refrigerants which have been known to be hazardaous to our living environment. Another acrylic 110 mm diameter tube once recorded 8o C with the ambient held at 23o C. The cooling in the first system was repeatable but not significant enough for practical applications. However, with no refrigerants used and its relatively simple manufacturing, a thermoacoustic cooling system is a potentially clean cooling system to be further investigated for practical or specific applications.