Heater Chip with Different Microchannels Geometries for a Low Pressure Free Molecular Micro-Resistojet
Dadui Cordeiro Cordeiro Guerrieri (TU Delft - Space Systems Egineering)
Marsil A.C. de Athayde Costa e Silva (TU Delft - Space Systems Egineering)
B.T.C. Zandbergen (TU Delft - Space Systems Egineering)
Angelo Cervone (TU Delft - Space Systems Egineering)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
This paper presents a dynamic system approach for the modeling of fluid flow in microchannels to be used in thrust control applications. A micro-resistojet fabricated using MEMS (Microelectromechanical Systems) technology has been selected for the analysis. The device operates by vaporizing a liquid propellant, in this case water, and expelling it as gas that is accelerated by a micro-nozzle. The pressure variation due to boiling in the chamber might lead to unwanted behavior of the feed system and the frequency analysis in this case can indicate whether or not instabilities will be present. To handle this complex problem, the incompressible Navier-Stokes equations are linearized in the steady-state flow regime and then formulated in state space form to provide the necessary means for control analysis. Controllability and observability of the system are investigated considering low values of Reynolds numbers present in micro fluidics applications. Results from the analytical treatment are compared with CFD (Computational Fluid Dynamics) simulations of the microchannel to demonstrate the validity of the approach investigated.