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Manusia modern membutuhkan piranti elektronik berukuran kecil yang mudah dibawa. Roadmap Teknologi SIA mengantisipasi setelah tahun 2011 frekuensi chip piranti elektronik mikro akan melebihi 17 Ghz dan dapat menghasilkan fluks panas lebih dari 90 W/cm2 dengan junction temperatur sebesar 100 celcius. Salah satu alternatif baru untuk mengurangi panas tersebut adalah dengan memanfaatkan efek vortek yang dihasilkan jet sintetik. Jet sintetik merupakan teknologi yang berbasis pada eksitasi membrane pada celah sempit guna menciptakan aliran vortek untuk mempercepat perpindahan panas dari sebuah heatsource

This research investigated the forced cooling characterization of an impinging synthetic jet under combined wave excitation. The synthetic jet cooling used an air flowing in a vertical direction into the heated wall. The synthetic jet actuator used two oscilating membranes to push and pull the air from and to the cavity. 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 application due to its advantage for having a small form factor and low noise. The investigation combined computational and experimental works. The model was simulated to examine the distribution of heat flow on the impinged walls using variation of turbulence model i.e. standard k-epsilon, realizable k-epsilon, standard k-omega and k-omega SST (Shear Stress Transport). Meshing order was elements tri and type pave and the number of grid was 4473 mesh faces to ensure detail discretization and more accurate calculation results. In the experiment the variation of sine and square wave signals were generated with sweep function generators to oscillate the membrane. The frequency of sine wave excitation for the first membrane was kept constant at 80 Hz, meanwhile the second membrane was excitated with varied square wave signals at 80 Hz, 120 Hz, and 160 Hz. Furthermore the velocity amplitude was 0.002 m/s. Some results indicate significant influence of the excitation, and combined waveform to the rate of heat transfer obtained.

This research investigated the flow and convective heat transfer characteristics of an impinging synthetic jet with different excitation modes. The synthetic air jet was generated by a vibrating membrane which pushed out the air from the cavity through the exit nozzles with oscillatory motion. 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. The model was simulated to examine the distribution of heat flow on the impinged walls using a turbulent model of k-ω SST. Meshing order was elements Tet/Hybrid and type Tgrid and the number of grid was more than 230 000 in order to ensure detail discretization and more accurate calculation results. In the experiment, sinusoidal and triangular waveform were generated with a function generator to oscillate the membrane. The frequency of membrane vibration were 80 Hz, 120 Hz, 160 Hz and the velocity amplitude was 1 m/s. Some results indicated significant influence of the excitation waveform
to the rate of heat transfer obtained.