Micro Propulsion

Bayt RL, Breuer KS (2001) Analysis and testing of a silicon intrinsic point heater in a micro propulsion application. Sens Actuators A 91 249-55... 

Micro power generation Power MEMS Micro heat engines Microengines Micro fuel cells Micro energy harvesting Micro energy scavenging Micro propulsion Micro coolers... 

In contrast to gas thrusters, ion thrusters accelerate charged particles with an electrostatic field. This approach leads to the highest /gp but typically very low thrust levels. Thrusters can be used in either continuous or pulsed operation, according to the application. Miniature rocket launchers and micro air vehicles require a continuous thrust and are best served by a unique thruster or engine with a continuous feed of propellant. Alternatively, digital micro-propulsion refers to an array of single-use thrusters that provide a small impulse (short burst of thrust) to accurately orient a small spacecraft or correct a vehicle s trajectory. 

In this article, we provide an overview of the various engineering issues and challenges surrounding the modeling, design and fabrication of micro-propulsion systems and supersonic micro-nozzles in particular. From this, it is our hope and intent that the reader will develop an appreciation for the unique aspects of supersonic nozzle behavior on the micro-scale. 

We close this article with a brief discussion concerning future research opportunities and needs for supersonic micro-nozzle flow within the context of micro-propulsion applications. In some instances preliminary work has been reported in various forms within the aerospace literature, however comprehensive and detailed studies have not yet appeared. 

Alkaline salts of bis(furoxano)-2-nitrophenol (primarily KBFNP) were proposed as heavy metal-free primary explosives. Even the most promising candidate— KBFNP—exhibits low thermal stability at temperatures over 100 °C and even more importantly it has a very low performance in comparison with LA. As an unsuitable LA replacement, it may find some use in igniting compositions replacing LS. KBFNP has been also investigated for use in actuators or micro-propulsion systems [54],... 

Moreover, there is a current need of miniaturized propulsion system for widening the capabilities of low cost micro-satellites. Recently, the development of a turbo-pump fed miniature rocket engine has been proposed as a new propulsion system for micro-satellites (10 to 100 kg) [6] the bipropellant tlmister uses 70 wt.-% H2O2 as oxidizer and ethanol as fuel. The engine displays four sub-components (i) two propellant micro-pumps, (ii) a HP decomposition chamber, (iii) a turbine coupled to an electric power generator and driven by the hot gas released from HP decomposition, and (iv) a thruster for the combustion reaction. 

Figure 1.9 summarizes the energy and power demands of micro, mild and full HEVs, as well as of plug-in HEVs [79]. With the increase of the contribution of the electric motor to car propulsion, the power and energy demands to the battery increase abruptly. They are flie highest for full and plug-in HEVs. 

Gassend, B. L. P. (2007). A fully micro fabricated two-dimensiraial electrospray array with applications to space propulsion, PhD submitted to Massachusetts Institute of Technology. 

Rarefied analyses of thermal coupling between the micro-nozzle with the surrounding substrate have also been reported [10]. In this work, steady low Reynolds number gas flows were again modeled by the DSMC approach, and the substrate transient thermal response was governed by the heat conduction equation. It was shown that propulsive efficiencies of the micronozzle decreased with higher nozzle wall temperatures and vice versa. These results are in agreement with the continuum-based heat transfer results previously discussed. 

Hmby MG-CV, Falkos P, Shenoy S. Micro newton colloid thruster system development. 27th international electric propulsion conference. 2001. 

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