The buckling torque may be much less than the yield torque in very thin rectangular tubes under torsion. In this paper, simple closed-form formulae are presented for buckling analysis of long hollow rectangular tubes under torsion. By the presented formulae, one can obtain the critical torque or the critical angle of twist of the tube in terms of its geometrical parameters and material constant...

In this paper, numerical solution of beta-type Stirling engine was presented considering its non-ideal regenerator. To this end, the second-order model including heat and power losses was used. Then, a numerical code was applied for calculating geometrical and physical optimum values of the engine. To confirm the obtained results, the physical and geometrical parameters of the GPU-3 engine were...

This paper presents a parameter study for optimum rotor geometrical parameter combinations of a refrigeration helical twin screw compressor with four commonly used lobe combinations and five different length/diameter ratios and wrap angles. The volumetric and indicated efficiencies of the compressor are important. So also are other factors such as rotor deflection, bearing load, bearing life an...

Mini and micro robots, which can swim in an underwater environment, have drawn widespread research interests because of their potential applications to the clinical drug delivery, biotechnology, manufacturing, mobile sensor networks, etc. In this paper, a prototype of microrobot based on the motion principle of living microorganisms such as E. Coli Bacteria is presented. The properties of this ...

An inverse problem motivated by the nondestructive testing (NDT) of adhesively bonded structures used in the aircraft industry is studied. Using transmission line theory, a model is developed which, when supplied with electrical and geometrical parameters, accurately predicts the reflection coefficient associated with such structures. Particular attention is paid to modelling the connection bet...

Nowadays, numerical modelings play a key role in analyzing hydraulic problems in fractured rock media. The discrete fracture network model is one of the most used numerical models to simulate the geometrical structure of a rock-mass. In such media, discontinuities are considered as discrete paths for fluid flow through the rock-mass while its matrix is assumed impermeable. There are two main pa...