Deriving the Generalized Power and Efficiency Equations for Jet Propulsion Systems

Jong

Chang

et al. 2009

Self Cite

Fish have appeared since Precambrian more than 500 million years ago. Yet, there are still much untamed areas for fish propulsion research. The swordfish has evolved a light thin/high crescent tail fin for pushing a large amount of water backward with a small velocity difference. Together with a streamlined forward-enlarged thin/high body and forwardbiased dorsal fin enclosing sizable muscles as the power source, the swordfish can thus achieve unimaginably high propulsion efficiency and an awesome maximum speed of 130 km/h as the speed champion at sea. This paper presents the innovative concepts of ''kidnapped airfoils'' and ''circulating horsepower'' using a vivid neat-digit model to illustrate the swordfish's superior swimming strategy. The body and tail work like two nimble deformable airfoils tightly linked to use their lift forces in a mutually beneficial manner. Moreover, they use sensitive rostrum/lateral-line sensors to detect upcoming/ambient water pressure and attain the best attack angle to capture the body lift power aided by the forwardbiased dorsal fin to compensate for most of the water resistance power. This strategy can thus enhance the propulsion efficiency greatly to easily exceed an astonishing 500%. Meanwhile, this amazing synergy of force/beauty also solves the perplexity of dolphin's Gray paradox lasting for more than 70 years and gives revelations for panoramic fascinating future studies.

“…This section uses the advanced jet propulsion concepts of Lee et al 32) and discusses swordfish propulsion. First, from Fig.…”

Section: Lagrangian Reynolds Transport Equationmentioning

confidence: 99%

Section: Lagrangian Reynolds Transport Equationmentioning

confidence: 99%

“…16. 32) When AEF is the net force of the jet propulsion system, this force is assumed to be forward positive.…”

Section: Momentum Equation For Jet Propulsion Systemmentioning

confidence: 99%

Section: )mentioning

confidence: 99%

Section: )mentioning

confidence: 99%

See 3 more Smart Citations

Propulsion Strategy Analysis of High-Speed Swordfish

Jong

Chang

et al. 2009

Self Cite

Integrated Energy Method for Propulsion Dynamics Analysis of Air-Pressurized Waterjet Rocket.

Chiu

Hsia

2001

Self Cite

The launching of a waterjet rocket has been a very popular idea in recent years. Its basic propulsion principle makes use of the high-pressurized air inside the rocket's main body to swiftly expel the water out of the nozzle and thus generate thrust. The waterjet rocket is characterized with nature, interest, combustionlessness, environmental friendliness, simplicity, and minimal cost. Moreover, it is a very good science model for propulsion analysis, design, experiment, and education because of an abundance of easily adjustable key parameters. This model also features separately stored energy and mass of the propellant, in contrast to a conventional rocket. However, related literature shows that no indepth theoretical analysis of the waterjet rocket has been attempted for various reasons. In this research, the propulsion dynamics of a waterjet rocket is analyzed by simultaneously solving the momentum and the newly derived generalized power equations to predict its flight histogram, computationally, and convolutionally. This integrated energy approach synthesizes the internal and external dynamics analyses together and ingeniously takes full advantage of the clear power supply of pressurized air in a waterjet rocket. The analysis results are generally agreeable with the experimental flight data. While the new power equation herein gives a complete spectrum of physical parameters to be manipulated, there will be wider room in quest of better rocket propulsion performance, especially through the heuristic research of this versatile but affordable waterjet rocket.

Propulsion Superiority Analysis of U-turn Launch Mode for Satellite Rocket

Yuan

Lin

2008

Self Cite

This paper is based on the concepts of lagrangian Reynolds transport equation (LRTE), momentum, and the generalized total kinetic power of a rocket. The wood rocket model is used as a vivid model to explain propulsive efficiency of a rocket. We prove that the novel U-turn launch mode can convert total kinetic power and gravitational potential energy into rocket propulsive power. Furthermore, we use the first stage rocket engine of the Saturn V as an example to simulate and analyze its propulsive efficiency computationally with Matlab software. In conclusion, this revolutionary launch mode has the potential to dramatically improve the propulsive efficiency of launch vehicles.