Ji C.,Zhejiang University |
Zou J.,Zhejiang University |
Ruan X.D.,Zhejiang University |
Dario P.,CRIM Laboratory |
Fu X.,Zhejiang University
Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy | Year: 2011
The slip phenomenon will result in a deviation of the theoretical head; thus, it is usually considered as an important factor in the design process of turbomachines (compressor, pump, or turbine). A new correlation for the slip factor in radial and mixed-flow impellers is developed in this study, which is derived on the basis of the Euler equation in turbomachinery and relative eddy theory. It is a function of flow coefficient besides geometric parameters, enabling it to predict the varying trend of slip factor with flowrate accurately, and is applied to several cases for validation. © Authors 2011.
Li F.,Zhejiang University |
Liu W.,Zhejiang University |
Fu X.,Zhejiang University |
Bonsignori G.,CRIM Laboratory |
And 3 more authors.
Mechatronics | Year: 2012
This paper presents a bio-inspired design of a jumping mini robot including the theoretical analysis on jumping dynamics based on a simplified biological model, the dynamically optimized saltatorial leg design, the overall design of the jumping robot prototype and, as a part of the bio-mimetic research, and the measuring and comparing of the jumping characteristics between the robot and animal. The artificial saltatorial leg is designed to imitate the characteristics of a real jumping insect, kinematically and dynamically, and proposed to reduce the contact force at tarsus-ground interface during jumping acceleration thus optimizes the jumping motion by minimizing the risk of both leg ruptures and tarsus slippage. Then by means of high speed camera experiment, the jumping characteristics of the theoretical jumping model, the jumping insect leafhopper and the robot are compared so as to show the dynamic similarity and optimization results among them. The final energy integrated jumping robot prototype is able to accomplish a movement of continuous jumping, of which a single jumping reaches 100 mm high and 200 mm long, about twice and four times of its body length respectively. © 2012 Elsevier Ltd. All rights reserved.