In the investigations of fish swimming, relationship between swimming and corresponding characteristics flow field attracts lots attention. this paper, influence different Strouhal numbers on mechanical fish-like body is investigated. It found that strength anti-Karman vortex thrust are affected by number. When number small, coefficient small but propulsion efficiency high. Similarly, when larg...

TBM boreability and performance prediction has always been a hot research topic. In this paper, taking one large diameter long tunnel excavated by gripper hard rock in Northeastern China as background, based on number of boring data site mono-factorial regression analysis the correlations among Field Penetration Index (FPI) geological parameters, multi-factorial correlation formula FPI with uni...

Hatchling sea turtles emerge from nests, crawl down the beach and enter the sea where they typically enter a stereotypical hyperactive swimming frenzy. During this swim the front flippers are moved up and down in a flapping motion and are the primary source of thrust production. I used high-speed video linked with simultaneous measurement of thrust production in tethered hatchlings, along with ...

In this paper particle swarm optimization (PSO) is used for a design optimization of a linear permanent magnet synchronous motor (LPMSM) considering ultra low thrust force ripples, low magnet consumption, improved efficiency and thrust. The influence of PM material is discussed, too and the modular poles are proposed to achieve the best characteristic. PM dimensions and material, air gap and mo...

A host of information is now available regarding the geological and thermal structure as well as deformation rate across the Himalaya of central Nepal. These data are reconciled in a two-dimensional mechanical model that incorporates the rheological layering of the crust which depends on the local temperature and surface processes. Over geological timescale (5 Ma) the ""'20 mm/yr estimated shor...

[1] Mars Orbiter Laser Altimetry (MOLA) data have been used to characterize lobate scarps along the dichotomy boundary in the eastern hemisphere of Mars. These structures are the surface expression of thrust faulting of the southern highlands. Displacement on the thrust faults is generally less than 1 km except in the case of the Amenthes Rupes thrust fault, where the maximum displacement is on...

Supersonic retropropulsion provides an option that can potentially enhance drag characteristics of high mass entry, descent, and landing systems. Preliminary flow field and vehicle aerodynamic characteristics have been found in wind tunnel experiments; however, these only cover specific vehicle configurations and freestream conditions. In order to generate useful aerodynamic data that can be us...

Pulsed plasma thrusters (PPTs) are the simplest electric acceleration devices with solid propellant on satellites. In order to make their thrust performance higher and to feed propellant more effectively, we have been developing a new type PPT using powdered propellant. To estimate its thrust performance, we have made a test model thruster for comparing the thrust performances of PPTs with soli...

This paper reports comparative experiments with two novel and one conventional thrust control algorithms for the unsteady (transient) control of thrust generated by conventional bladedpropeller marine thrusters. First, comparative experiments with three different thrust control algorithms over a wide range of unsteady operating conditions suggest that model-based control algorithms offer transi...