The motion of self-propelled tubular micro- and nanojets has so far been achieved by bubble propulsion, e.g., O2 bubbles formed by catalytic decomposition of H2O2, which renders future biomedical applications inviable. An alternative self-propulsion mechanism for tubular engines on the nanometer scale is still missing. Here, we report the fabrication and characterization of bubble-free propelle...

A practical online optimization scheme is developed for performance optimization of an electrical aircraft propulsion system. The goal is to minimize the power extraction of the propulsion system for any given thrust value. The online optimizer computes the optimum pitch angle of a variable pitch propeller by minimizing the power of the system for a command thrust value. This algorithm is teste...

A Microelectromechanical System-based (MEMS) PICOSAT Inspector (MEPSI) picosatellite on STS-116, in December 2006, used a five thruster cold gas propulsion system to translate and rotate. The inspector picosatellite measured 4 x 4 x 5 inches in dimension and weighted 1.4 kg. Our propulsion system was produced by a unique (to spacecraft) method of manufacturing that is low cost, tightly integrat...

We study the state behaviour of self-propelled and Brownian squares as a function of the magnitude of self-propulsion and density using Brownian dynamics simulations. We find that the system undergoes a transition from a fluid state to phase coexistence with increased self-propulsion and density. Close to the transition we find oscillations of the system between a fluid state and phase coexiste...

High-speed permanent magnet synchronous machines are of great interest in the applications where high utilization factor and e ciency are required. Depending on application, power requirements change from kilowatts to megawatts. To investigate power limits of high-speed machines, the present feasibility study focuses on a 20 megawatt (MW) electric drive for marine propulsion. However, in additi...

The current emphasis on small, low-cost planetary missions using Delta and Medlite Class launch vehicles has prompted the examination of the use of Solar Electric Propulsion (SEP) spacecraft to either enable or enhance the performance of some of the more demanding planetary missions. Planetary missions that appear most attractive for a small solar electric propulsion system include those missio...

The Space Shuttle Integrated Main Propulsion System (IMPS) consists of the External Tank (ET), Orbiter Main Propulsion System (MPS), and Space Shuttle Main Engines (SSMEs). The IMPS is tasked with the storage, conditioning, distribution, and combustion of cryogenic liquid hydrogen (LH2) and liquid oxygen (LO2) propellants to provide first and second stage thrust for achieving orbital velocity. ...

The effect of fuel to oxidiser ratio on the thrust performance of a novel CubeSat propulsion system is presented in this paper. This propulsion system uses aluminium wool as fuel and a mixture of water and sodium hydroxide as oxidiser. The goal of the experiment is to determine the effect of fuel to oxidiser ratio on the thrust profile of the device, as measured with a pendulum type thrust bala...

The quest for swimming microrobots originates from possible applications in medicine, especially involving navigation in bodily fluids. Swimming microorganisms have become a source of inspiration because their propulsion mechanisms are effective in the low-Reynolds number regime. In this study, we address a propulsion mechanism inspired by metachronal waves, i.e. the spontaneous coordination of...