Experimental Study of a Microchannel Bubble Injector for Microgravity Applications

We perform a quantitative characterization of a microbubble injector in conditions relevant to microgravity. The injector pregenerates a slug flow by using a capillary T-junction, whose operation is robust to changes in gravity level. We address questions regarding the performance under different injection conditions. In particular we focus on the variation of both gas and liquid flow rates. The injection performance is characterized by measuring bubble injection frequency and bubble sizes. We obtain two distinct working regimes of the injector and identify the optimal performance as the crossover region between them. S. Arias (B) Escola Politècnica Superior de Castelldefels, Universitat Politècnica de Catalunya, Barcelona, Spain e-mail: [email protected] S. Arias · L. Ramírez-Piscina · R. González-Cinca Space and Aeronautics Research Centre, CRAE, Barcelona, Spain X. Ruiz Área de Física Aplicada, Universitat Rovira i Virgili Tarragona, Tarragona, Spain X. Ruiz · J. Casademunt · L. Ramírez-Piscina Institut d’Estudis Espacials de Catalunya, IEEC, Barcelona, Spain J. Casademunt Departament d’Estructura i Constituents de la Matèria, Facultat de Física, Universitat de Barcelona, Barcelona, Spain L. Ramírez-Piscina · R. González-Cinca Departament de Física Aplicada, Universitat Politècnica de Catalunya, Barcelona, Spain