Numerical and experimental investigation of the effect of channel geometry on cavity formation in microfluidic channels
Embargo Lift Date: 2020-12-05
Erdem, E. Yegan
Item Usage Stats
MetadataShow full item record
Cavitation formation in low pressure regions of a ﬂow is a chaotic distortion in ﬂuid mechanics. Due to the complicated nature of multiphase ﬂows, its modelling is expensive in terms of time and computational power. Opensource softwares such as OpenFOAM reduce license expenses and provide a developer friendly environment to simulate these types of complicated ﬂows. In this thesis, by using OpenFoam software, several diﬀerent geometries that cause cavitation are investigated. Presented results are compared with both literature and supported by experimental results. Experiments are carried out in microﬂuidic chips that are fabricated with soft lithography technique; ﬂuorescent particles were introduced in the ﬂow and cavity formation was observed under a ﬂuorescent camera. Results showed that, OpenFOAM is well capable of predicting the cavitation formation in small scales. It was observed that increasing channel width reduces the pressure diﬀerence causing bubbles to form in higher input pressures. It was also seen that decreasing the channel width causes friction and viscous forces to dominate and reduce the velocity of ﬂuid preventing the cavitation to form. Overall the modelling of cavity formation in microchannels with varying width and cross sectional proﬁle were successfully accomplished and results were veriﬁed with experiments.