Welcome to CRAFT-Tech

CRAFT Tech has been involved in the development of sophisticated multi-phase capabilities for a variety of applications. For gas/solid flows, i.e. gas phase carrier fluid with dispersed particulate phase, both Eulerian and Lagrangian solvers are available. The gas/particulate interactions are solved in a strongly coupled fashion with velocity and temperature non-equilibrium effects accounted for. Furthermore both "dense" and "dilute" particulate concentrations are permitted: in the former the solid phase has significant volumetric fashion and applications include fluidized beds and gun chamber flowfields. In other examples such as rocket exhaust plumes, the volumetric fraction of the particulates are low even though the mass loading is very high.

Gas/Liquid multi-phase capabilities encompass interactions of a gas phase with both bulk liquid as well as sprays. In the former, the bulk liquid is a continuum fluid and the evolution of the gas/liquid interface is simulated with generation of droplets at the interface. The spray capability has both Eulerian and Lagrangian solvers with non-equilibrium effects including detailed non-equilibrium vaporization models. The range of applications include combustion instability problems in liquid propellant systems, dispersion and vaporization of toxic chemical and biological agents, etc.

Another multi-phase problem in which we have developed advanced models is cavitation. This involves a liquid carrier phase with gas phase bubbles that grow when liquid pressure drops below its vapor pressure. This work is focused towards simulating cavitation in cryogenic fluids where thermal effects due to cavitation are significant and strong variation in liquid and vapor properties are present. Furthermore advanced models to integrate bubble dynamics within the context of dense cavitating clouds have been developed. Applications include liquid rocket turbopump simulations, commercial axial and centrifugal pumps, and marine propellers.