Optimal operation of turbopumps is crucial for all liquid fuel rocket engines. To reduce weight, these pumps often operate at critical conditions, where dynamic instability and cavitation are unavoidable. In cryogenic engines, the fuel and oxidizer used are liquid usually hydrogen and liquid oxygen at very low temperatures (about 14 and 90 K, respectively). Usually we treat cavitation as an isothermal phenomenon, but this assumption is not valid for such propellants: flows are characterized by a substantial cooling during the vaporization process due to cavitation. This phenomenon delays the further development of cavitation, so it plays a moderation role in the cavitation increase. The numerical prediction of the thermal effect is therefore a major industrial issue.
The first project outcome is the experimental basis containing results of thermodynamic effect in cavitating flow and its influence on the cavity dynamics. The other application is the development of a numerical tool that will enable to take into account the cavitation erosion effects. We will carry out direct measurements of thermodynamic effects in the developed cavitating flow. Previous studies have addressed this issue only indirectly by comparing results obtained in water and in thermosensible media. The equipment and experience we have available in the LVTS, enables to measure the temperature effects directly and thus to construct a better basis for evaluation of the results of numerical predictions. Direct users of the results are researchers and industry that are dealing with cavitation erosion and specific topics of cavitating flow.
|High speed visualization and measurements of temperature fields during cavitation bubble growth and collapse.|
PETKOVŠEK, Martin, DULAR, Matevž. IR Measurements of the Thermodynamic Effects in Cavitating flow. International Journal of Heat and Fluid Flow, In Press, DOI: http://dx.doi.org/10.1016/j.ijheatfluidflow.2013.10.005 [PDF]
DULAR, Matevž, COUTIER-DELGOSHA, Olivier. Thermodynamic effects during growth and collapse of a single cavitation bubble. Journal of Fluid Mechanics, 2013, vol. 736, pp. 44–66 [PDF]
Partners: Le Laboratoire des Ecoulements Geophysiques et Industriels (LEGI), Grenoble, France
Duration: 2011 – 2015