Hasil Pencarian  ::  Simpan CSV :: Kembali

"A greater heat load due to the miniaturization of electronic products causes the need for a new cooling system that works more efficiently and has a high thermal capacity. A synthetic jet is potentially useful for the cooling of electronic components. This paper reports the results of our experimental studies and the influence of orifice shape for Impinging Synthetic Jet cooling perfomance. The effect of shape of the orifice of an impinging synthetic jet assembly on the apparatus cooling of a heated surface is experimentally investigated. It will be seen that the characteristics of convective heat transfer will occur by moving the piezoelectric membrane. The prototype of the synthetic jet actuator is coupled with two piezoelectric membranes that operate by 5 volt electrical current and create a sinusoidal wave. The orifice shapes considered are square and circular. The results show the significant influence of orifice shape and sinusoidal wave frequencies on the heat transfer rate that were obtained. The temperature drop with a square orifice is found to be larger than that with circular shapes. A square orifice has a larger covered area if compared to the circular orifice at the same radius, thus resulting in a larger entrainment rate that leads to an increase of heat transfer performance."

"ABSTRAKSistem pendinginan konvesional dengan menggunakan fan dianggapsudah tidak lagi efektif dan memadai untuk diaplikasikan dewasa ini.Miniaturisasi produk dengan performa kinerja yang semakin canggihmenyebabkan diperlukannya sistem pendingin baru yang mempunyai efisiensi termal yang tinggi dan juga hemat energi. Synthetic jet dapat dijadikan sistem pendinginan baru berdasar input massa netto nol tetapi momentum tidak nol.Dalam penelitian ini dua buah membran jet sintetik dengan tipe aliran impinging akan digetarkan dengan menggunakan variasi gelombang sinusoidal dan square. Penelitian akan dilakukan dengan menggunakan komputasional dan eksperimental. Pada tahap komputasional penelitian ini menggunakan software CFD Fluent dengan model turbulensi k-w SST dengan elemen meshing Tet/Hybrid tipeTgrid, sedangkan pada tahap eksperimental menggunakan function generator untuk menggerakkan membran dengan menggunakan fungsi variasi Sinusoidal dan Square serta tiga frekuensi osilasi yaitu 80 hz, 120 hz, dan 160 hz pada amplitudo tetap 1 m/s. Hasil eksperimen menunjukkan adanya pengaruh gelombang dan frekuensi osilasi yang signifikan terhadap laju perpindahan panas yang terjadi. Laju perpindahan panas/pendinginan terbaik terjadi pada frekuensiosilasi yang lebih rendah; dalam penelitian ini pada gelombang Sinusoidal 120 Hz ? Square 80 hz.

---

ABSTRACTNowadays, the conventional fan-based cooling is no longer efective andapplicable. Miniaturization with higher performance of electronic products causes the need for a new cooling system that high thermal efficiency and low energy consumption. Synthetic jet is a new cooling system based on zero netto mass input but non zero momentum. An impinging synthetic jet which has two membranes will oscillate using two variation of sinusoidal and square wave. This research was conducted both in computational and also experimental stage.Computational stage was conducted by Fluent CFD Fluent software with turbulence model k-w SST with meshing elements Tet/Hybrid type TGrid, while in the experimental the function generators will used to drive the membranes with the variation of sinusoidal and square wave in three oscillation frequencies: 80 hz, 120 hz, and 160 hz at fixed amplitude of 1 m/s. The experimental results show significant effect of wave and oscillation frequency on the heat transfer ratethat occured. The best heat transfer rate / cooling effect occurs at a lower oscillation frequency; in this study at Sinusoidal 120 Hz ? Square 80 hz."

"Kebutuhan akan sistem pendinginan pada masa kini sangat penting terkait meningkatnya beban panas akibat miniaturisasi produk alat ? alat elektronik. Sistem pendinginan konvensional berbasis fan telah mencapai batas efisiensinya dan dibutuhkan teknik pendinginan baru. Synthetic jet merupakan sistem pendinginan baru berdasar input massa netto nol tetapi momentum tidak nol. Dalam penelitian ini sebuah impinging synthetic jet digetarkan dengan fungsi gelombang triangle. Penelitian dilakukan dalam dua tahapan yaitu komputasional dan eksperimental. Tahapan komputasional bertujuan untuk melihat distribusi aliran panas synthetic jet. Tahapan eksperimental bertujuan untuk mendapatkan karakterisasi synthetic jet. Pada tahap komputasional penelitian ini menggunakan software CFD Fluent dengan model turbulensi k-w SST dengan elemen meshing Tet/Hybrid tipe Tgrid, sedangkan pada tahap eksperimental menggunakan function generator untuk menggerakkan membran dengan tiga frekuensi osilasi yaitu 80 hz, 120 hz, dan 160 hz pada amplitudo tetap 1 m/s. Hasil eksperimen menunjukkan adanya pengaruh gelombang dan frekuensi osilasi yang signifikan terhadap laju perpindahan panas yang terjadi. Laju perpindahan panas/pendinginan terbaik terjadi pada frekuensi osilasi yang lebih rendah; dalam penelitian ini pada frekuensi 80 hz.

---

The need for cooling in the present system becomes very important as the consequence of the increased heat load due to product miniaturization of electronics devices. Conventional fan-based cooling system has reached the limit of its efficiency and needed a new cooling technique. Synthetic jet is a new cooling system based on zero netto mass input but non zero momentum. In this study an impinging synthetic jet was vibrated with a triangle function. The study was conducted in two stages, computational and experimental. Computational stage aims to look at the distribution of heat flow of synthetic jet. Experimental stage intended to obtain characterization of synthetic jet. In the computational stage the research using CFD Fluent software with a turbulence model k-w SST with meshing elements Tet/Hybrid type TGrid, while in the experimental stage it used the function generator to drive the membrane with three oscillation frequency: 80 hz, 120 hz, and 160 hz at fixed amplitude of 1 m/s. The experimental results show significant effect of wave and oscillation frequency on the heat transfer rate that occured. The best heat transfer rate / cooling effect occurs at a lower oscillation frequency; in this study at a frequency of 80 hz. "