Developing headers to uniformly distribute two-phase (liquid/vapor) flow is a difficult but important aspect in the design of advanced two-phase thermal control systems. This paper documents experimental efforts toward developing a header to equally distribute the liquid flow to parallel legs of a two-phase heat exchanger. Models of various header concepts were built and tested using air/water mixtures to simulate two-phase liquid/vapor flow. Based on the results of these tests, a Fan Header concept was designed for a specific, parallel tube heat exchanger. At flow rates within the expected range of operation, this Fan Header distributed the liquid within 16% of the equally distributed value for inlet qualities up to 25%.
