Numerical Simulations of Supersonic Flow in a Linear Aerospike Micronozzle

In this study, we numerically examine thrust performance of the linear aerospike nozzle micro-thruster for various nozzle spike lengths and flow parameters in order to identify optimal geometry(s) and operating conditions. Decomposed hydrogen-peroxide is used as the monopropellant in the studies. Performance is characterized for different flow rates (Reynolds numbers) and aerospike lengths, and the impact of micro-scale viscous forces is assessed. It is found that 2-D full micro-aerospike efficiencies can exceed axisymmetric micro-nozzle efficiencies by as much as 10%; however, severe penalties are found to occur for truncated spikes at low Reynolds numbers

CFD modelling of condensers for freeze-drying processes

The aim of the present research is the development of a computational tool for investigating condensation processes and equipments with particular attention on freeze-dryers. These condensers in fact are usually operated at very low pressures, making it difficult to experimentally acquire quantitative knowledge of all the variables involved. Mathematical modelling and CFD (Computational Fluid Dynamics) simulations are here used to achieve a better comprehension of the flow dynamics and of the process of ice condensation and deposition in the condenser, in order to evaluate condenser efficiency and gain deeper insights on the process to be used for the improvement of its design. Both a complete freeze-drying apparatus of laboratory-scale and an industrial-scale condenser have been investigated in this work, modelling the process of water vapour deposition. Different operating conditions have been considered and the influence exerted by the inert gas as well as other parameters have been investigate