Characterization of Material Properties Using Multiple Wavelength Interferometry

In microgravity, the performance of a constrained vapor bubble heat pipe is limited by the effect of Marangoni forces. This limit can potentially be overcome by using a mixture, rather than a pure fluid, in order to create a concentration gradient which offsets the temperature gradient. However, it is difficult to fully understand this change in concentration along the length of a pipe. In this project, multiple wavelength interferometry was used to examine the thickness and composition of the liquid film in a constrained vapor bubble heat pipe. A new application of multiple wavelength interferometry to determine concentration of a fluid at any point was derived. An algorithm to apply this method and to calculate the liquid film thickness was created.