The flow structure and heat transfer performance of an oblique impinging jet generated in a square miniature channel

Communications network traffic is currently growing at an exponential rate, and an evolution of the current optical network infrastructure (backboned by Photonic Integrated Circuits PICs) is required to satisfy future bandwidth requirements. A core component of the PIC are the laser arrays, where approx. 0.1W is dissipated by each laser-bar over a small area (length scale approx. 10^-6m) resulting in a large heat flux (approx. 10^4 kW/m^2). Due to this large heat density, liquid cooling is the most feasible solution to achieve thermal control of these devices, and a suitable microfluidic system is currently being developed to enable next-generation PICs. Impinging jets are of interest in this system as a component of the primary heat exchanger. It is therefore important to investigate methods of practically generating, characterizing and controlling jet structures for the internal, laminar flow regime found in microfluidic applications. In this work, the geometry of a passively actuated valve structure (previously presented by the authors) was modified and used to generate an oblique jet that impinged on the top wall of a miniature channel. In the next section, the experiments performed to characterize this jet will be described, and this will be followed by the results, discussion, and conclusions.