Results 31 to 40 of about 195,565 (345)
Efficiency of fish propulsion [PDF]
Bioinspiration & Biomimetics, 2015 It is shown that the system efficiency of a self-propelled flexible body is ill-defined unless one considers the concept of quasi-propulsive efficiency, defined as the ratio of the power needed to tow a body in rigid-straight condition over the power it needs for self-propulsion, both measured for the same speed. Through examples we show that the quasi-
Maertens, Audrey +2 more
openaire +6 more sources
A Review of Concepts, Benefits, and Challenges for Future Electrical Propulsion-Based Aircraft
Aerospace, 2020 Electrification of the propulsion system has opened the door to a new paradigm of propulsion system configurations and novel aircraft designs, which was never envisioned before.
Smruti Sahoo, Xin Zhao, K. Kyprianidis
semanticscholar +1 more source
Study on Applicability of Energy-Saving Devices to Hydrogen Fuel Cell-Powered Ships
Journal of Marine Science and Engineering, 2022 The decarbonisation of waterborne transport is arguably the biggest challenge faced by the maritime industry presently. By 2050, the International Maritime Organization (IMO) aims to reduce greenhouse gas emissions from the shipping industry by 50 ...
Callum Stark +5 more
doaj +1 more source
Review of State-of-the-Art Green Monopropellants: For Propulsion Systems Analysts and Designers
Aerospace, 2021 Current research trends have advanced the use of “green propellants” on a wide scale for spacecraft in various space missions; mainly for environmental sustainability and safety concerns.
A. Nosseir, A. Cervone, A. Pasini
semanticscholar +1 more source
CFD Analysis of De Laval Nozzle of a Hybrid Rocket Engine [PDF]
E3S Web of Conferences: The study gives a general overview of the CFD-simulated gas flow via the nozzle of a De Laval rocket engine. In CFD software, the mesh is generated using the nozzle’s geometry.
Ahmad Mohamed Tarmizi +6 more
doaj +1 more source
Biology, 2022 Different movement speeds can contribute to different joint loading in sports. Joint contact force is the actual force acting on the articular surface, which could predict performance and injury, but is rarely reported for badminton overhead strokes ...
Xinze Cui +4 more
doaj +1 more source
Propulsion on a superhydrophobic ratchet [PDF]
Scientific Reports, 2014 Liquids in the Leidenfrost state were shown by Linke to self-propel if placed on ratchets. The vapour flow below the liquid rectified by the asymmetric teeth entrains levitating drops by viscosity. This effect is observed above the Leidenfrost temperature of the substrate, typically 200°C for water.
Dupeux, Guillaume +4 more
openaire +5 more sources
Swimmers’ Effective Actions during the Backstroke Start Technique
Sensors, 2023 The analysis of the external forces of swimming starts has revealed how swimmers propel themselves out of the block, but data should be properly interpreted to fully understand force-generation mechanisms.
Karla de Jesus +7 more
doaj +1 more source
The Kinky Propulsion of Spiroplasma [PDF]
Cell, 2005 Bacteria have evolved many different means of generating movement. In this issue of Cell, Shaevitz et al. (2005) describe the swimming movement of a helical bacterium called Spiroplasma. They discover that Spiroplasma propels itself by generating two temporally distinct kinks that travel the length of the bacterium. These results point to the existence
Charles W. Wolgemuth, Nyles W. Charon
openaire +3 more sources
Energies, 2020 Gas turbine engines are required to operate at both design and off-design conditions that can lead to strongly unsteady flow-fields and aerodynamic losses severely impacting performance.
Nishan Jain +6 more
doaj +1 more source