Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
Browse
2 results
Search Results
Now showing 1 - 2 of 2
Article Citation - WoS: 5Citation - Scopus: 6Active Heat Transfer Enhancement by Interface-Localized Liquid Dielectrophoresis Using Interdigitated Electrodes(Elsevier, 2022) Yenigün, Onur; Barışık, MuratWe introduced an active heat transfer control between graphene and water using interdigitated electrodes (IDEs). Oppositely charged co-planer electrodes embedded on a graphene surface created a non-uniform electric field. Resulted interface localized liquid dielectrophoresis (LDEP) perpendicular to surface enhanced the water/graphene coupling and decreased interfacial thermal resistance (ITR) substantially. We correlated the theoretical calculations of average electric field strength near surface with Kapitza values measured at corresponding electrode configurations. We obtained a unified linear variation of Kapitza as a function of average electric strength independent of electrode size and charge. By increasing the electric field strength, we measured up to 96% decrease of Kapitza near electrodes. Since the IDEs generated electric field was only interface localized, it required lower electrode charges than any parallel-plate capacitor systems. We showed that ITR remains effective in heat transfer behavior for systems as big as 100nm such that interface localized electric field can at least increase the heat removal 50% by eliminating the ITR from both graphene/water interfaces of a channel system. By converting hydrophobic few-layer graphene to super-hydrophilic condition with ultra-low Kapitza, current results are important for graphene-based materials considered for the solution of the thermal management problem of current and next generation micro/nano-electronics.Article Citation - WoS: 9Citation - Scopus: 12Void Fraction and Speed of Sound Measurement in Cavitating Flows by the Three Pressure Transducers (3pt) Technique(Elsevier, 2020) Esposito, Claudia; Yenigün, Onur; Gouriet, Jean-Baptiste; Steelant, Johan; Vetrano, Maria RosariaSpeed of sound and void fraction are two key parameters in the characterisation of two-phase flows. However, accurate measurements require either intrusive or complex techniques. This paper reports on the Three Pressure Transducers (3PT) technique, which derives the speed of sound by measuring pressure fluctuations and which, thanks to its robustness and simplicity, could be applicable in harsh conditions. Therefore, the aim of this paper is to study in detail the feasibility of this technique against its limits and constraints in a cavitating flow. First, a numerical assessment of the technique is proposed to determine both the optimal transducers configuration and the sampling frequency. Then, the implemented algorithm was applied to a two-phase air-water mixture with well-known properties. Finally, the 3PT algorithm was used to study the behaviour of a cavitating flow induced by an orifice. This last application highlighted the possibility to use this technique to characterize the bubble flow generated by an orifice without the use of any optical access and by using a very compact experimental arrangement. The results obtained are also qualitatively compared to the images of the flow simultaneously acquired by a high-speed camera.