Design and analysis of an electro-hydrodinamic fan

Vzporedno z rastjo procesorskih moči raste tudi gostota toplotnega toka v različnih elektronskih čipih in napravah. Ta toplotni tok je treba iz elektronskih naprav prek prenosnikov toplote učinkovito odvajati. Učinkovitost prenosa toplote s prenosnikov toplote lahko povečamo s prisilno konvekcijo zraka prek reber prenosnikov. Običajno se prisilna konvekcija zraka ustvarja z različnimi mehanskimi ventilatorji. Ventilatorji predstavljajo dodatno strojno opremo, ki zasede veliko prostora, poleg tega pa njegovi premikajoči deli povzročajo hrup in vibracije. Ena izmed obetavnih rešitev za zamenjavo mehanskih ventilatorjev je elektro-hidrodinamsko (EHD) črpanje. EHD-ventilatorji prenašajo energijo na zrak prek električnega polja, ki ga ustvarjamo z različnimi geometrijami elektrod. Za delovanje ne potrebujejo premikajočih se delov in zavzamejo manj prostora. Raziskali smo različne geometrije ventilatorjev in možnosti za uporabo pri hlajenju. V ta namen smo zasnovali in eksperimentalno preverili delovanje dveh različnih prototipov. Z uporabo EHD-ventilatorja žica–rebro smo v zasnovani merilni progi lahko dosegli hitrost zraka 0,48 m/s pri napajalni napetosti 8 kV. Z uporabo EHD-ventilatorja žica–mreža smo izmerili najvišjo hitrost zraka 1,83 m/s pri napajalni napetosti 15,7 kV, kar je primerljivo s standardnim ventilatorjem pri uporabi enake merilne proge. Z uporabo standardnega ventilatorja smo izmerili najvišjo hitrost 1,85 m/s pri napajalni napetosti 12 V. Ugotovili smo tudi, da ima standardni ventilator na sredini pretočnega prereza zmanjšano hitrost zraka na izstopu, medtem ko ima EHD-ventilator neprekinjen pretočni profil kvadratne oblike.With the constant rise of processing powers and consequentially heat flow densities in various electronic chips and appliances, there is an ever increasing need to efficiently remove heat from these appliances. We can improve the efficiency of heat transfer with forced convection of air around extended surfaces. Forced convection of air is usually induced through the use of mechanical fans. These fans take up a lot of space and produce vibrations and noise, because of their moving parts. One of the promising solutions to replace mechanical fans, is electro-hydrodinamic (EHD) pumping. EHD pumps and fans transfer energy to the air with the use of an electric field. The electric field is generated with the use of electrodes with different geometries. They don\u27t require moving parts to work, and they take up less space. In this study we researched different fan geometries and their potential for cooling applications. To assist towards that end, we fabricated and experimentally evaluated two different prototypes. In our experimental setup, we tested the wire-fin and wire-mesh fans. When using the wire-fin fan we could observe wind speeds up to 0,48 m/s, at an operating voltage of 8 kV. When using the wire-mesh fan we could observe wind speeds up to 1,83 m/s, at an operating voltage of 15,7 kV. The latter is comparable to the wind speed produced by a mechanical fan in the same experimental setup. In the case of the mechanical fan wind speeds of up to 1,85 m/s, at an operating voltage of 12 V, were observed. We also observed that, when using the standard fan, there was an area of reduced wind speed in the middle of the flow profile, while there was no such area present when using the EHD fan