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Sistem pendinginan konvesional pada piranti elektronik dengan menggunakan fan sudah tidak efektif dan memadai untuk diaplikasikan sekarang ini. Miniaturisasi produk dengan performa kinerja yang semakin canggih menyebabkan diperlukannya sistem pendingin baru yang mempunyai efisiensi termal yang tinggi dan juga hemat energi. Jet sintetik 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 silang (Cross-Flow) diuji dan dianalisa untuk membandingkan karakteristik efek pendinginan yang masing-masing membran digetarkan dengan menggunakan variasi gelombang sinusoidal dan square. Penelitian dilakukan dengan menggunakan metode eksperimental. Tahap eksperimental menggunakan function generator untuk menggerakkan membran dengan menggunakan variasi fungsi frekuensi Sinusoidal dan Square pada masing-masing percobaan serta tiga frekuensi osilasi yaitu 80 Hz, 120 Hz, dan 160 Hz pada amplitudo tetap 0.002 m/s. Penelitian menggunakan jet sintetik ber-tipe aliran silang bertujuan untuk memperbaiki serta mengoptimumkan proses pendinginan jet sintetik akibat
adanya confinement effect atau efek sekam dimana panas yang dibuang akan terakumulasi kembali pada cavity dari jet sintetik sehingga pendinginan pada heatsink terhenti. Pada riset kali ini akan dilihat seberapa lama waktu optimum pendinginan jet sintetik ber-tipe aliran silang serta frekuensi osilasi ter-optimum dalam proses pendinginan heat sink.

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.

Synthetic jet which is based on zero netto mass input but non-zero momentum is a new approach
utilized for cooling system. The synthetic air jet was generated by vibrating membranes which pushed out the air from the cavity through the exit nozzles with oscillatory motion. This research investigated the forced cooling characterization of a cross flow synthetic jet using double membrane actuator with two different variations of sinusoidal and square wave and was conducted in computational as well as experimental stage. Computational stage was conducted by a commercial CFD software of Fluent® with a turbulence model k- ω SST with meshing elements quad type pave, while in the experimental work the function generators was used to drive the membranes with the variation of sinusoidal and square wave in three oscillation frequencies i.e 80 Hz, 120 Hz, and 160 Hz at fixed amplitude of 0.002 m/s. The experimental results show significant effect of the reduction of the confinement effect phenomena by using the cross flow synthetic jet. The best heat transfer rate, hence the optimum cooling effect was obtained at a lower oscillation frequency; in this study at sinusoidal 120 Hz – sinusoidal 120 Hz.

Numerical simulations and experimental methods are conducted to discover the effect of various
distance between the orifice and the heated plated (L). The investigation focusing on the characteristics of convective heat transfer by a synthetic jet circular orifice. The results is verified by the time history of convective heat transfer characteristic and validated against existing experimental results. The model was simulated to investigate the dispersion of heat flow on the walls using a mathematical turbulent model of k-w SST. The Reynolds number (Re) is in the range of 1421-2843 based on average velocity, while the normalized impinging distance varies between 0 and 3.3. The movement of the piezoelectric membrane is assumed of sinusoidal wave function. The results showed the significant influence of L/d Ratio and sinusoidal wave frequencies to the heat transfer rate obtained. At small axial distance (L), average Nusselts number decrease due to confinement effect. However, at larger axial distances, the synthetic jet velocity weaken which again reduces the convective heat transfer coefficient.

A Synthetic jet works based on a vibrating membrane inside a cavity and nozzle for the air outlet. The synthetic jet cavity interior has an important role to generate the air at sufficient conditions to do the cooling process. This research investigated the flow and convective heat transfer characteristics on four impinging synthetic jet prototype with different excitation modes of a sinusoidal waveform forcing. The main purpose of this synthetic jet was to create vortices pair to come out from nozzle which will accelerate the heat transfer process occurring at the impinged wall. This heat transfer enhancement principles became the basis to simulate an alternative cooling system to substitute the conventional fan cooling in electronic devices due to its advantage for having a small form factor and low noise. The investigation combined computational and experimental works. In the experiment sinusoidal waveform was used to oscillate the membrane and the wave frequency used were 80 Hz, 120 Hz, 160 Hz and the velocity amplitude was 1 m/s. Some results indicated significant influence of the cavity design, frequency excitation, and waveform to the rate of heat transfer obtained.