Application of the DSMC Method for Design of a Coaxial Microthruster Nozzle

Abstract

The Direct Simulation Monte Carlo (DSMC) method is used to numerically simulate and design a micronozzle with improved performance. Thrust calculations using the DSMC method demonstrate that the coaxial micronozzles can achieve milli-Newton thrust levels with specific impulses on the order of 45 s using argon in a cold gas expansion. Improved micronozzle designs of coaxial microthrusters are also proposed. Coaxial micronozzles utilizing center-body geometries to exploit pressure thrust show about 140% increase in specific impulse at low Reynolds numbers compared to a traditional converging nozzle.

The interaction of parallel and inclined planar rarefied sonic plumes—From free molecular to continuum regime

“…Especially in aerospace applications, three-dimensional clusters are common, the simulation of which involves significantly higher computational costs for a well-resolved DSMC. For three-dimensional plume clusters, a mitigation of shock effects is expected, as the gas can escape the shock region in another direction, while for three-dimensional toroidal aerospikes 63 an increase in the shock effect is expected, since a higher mass flux enters the interaction region. bounds the integration over velocity space to those velocities which may reach the point r. The corresponding domain is shown in Fig.…”

Cold gas microthruster

“…With the continuum assumption possibly breaking down, simulations based on the NaviereStokes equations will start to produce less accurate results. Thus, it was proposed to simulate the flow in the micronozzle using Direct Simulation Monte Carlo (DSMC) [37]. This method is a discrete probabilistic method that simulates single particles in a volume of fluid, each representing a predetermined amount of physical molecules.…”

Microspike Based Chemical/Electric Thruster Concept for Versatile Nanosat Propulsion

“…Once again this would lower Isp but this overlap of operating ranges means that the lifetime of a mission could be extended until all propellant is consumed. Plug-annular micronozzles or microspikes is a novel concept for increasing the specific impulse of cold gas and chemical microthruster [6] . Conventional macroscale bipropellant chemical or cold-gas propulsion systems commonly use gas expansion through converging-diverging de Laval nozzles.…”

“…[6] Other electric propulsion options such as the MEMSbased electrospray thruster arrays [7] can also be implemented in conjunction with the chemical microspike thruster.…”