We demonstrated a liquid lens whose focal length can be controlled by an actuator. The lens cell is composed of elastic membrane, planar glass plate, a periphery sealing ring, and a liquid with a fixed volume in the lens chamber. Part of the periphery sealing ring is excavated to form a hollow chamber which functions as a reservoir. This hollowed periphery is surrounded by an exterior rubber me...

Active and passive methods are two main mechanisms of heat transfer improvement. The active use external forces to improve transfer. This investigation evaluates the thermal frictional behavior a circular tube containing rotational shaft. Constant flux was exerted tube. fluid inlet outlet temperature as well wall tubes were measured calculate hat coefficient. Re (Reynolds) number between 800-20...

The presented paper deals with the use of physical modelling to study degassing process aluminium melts in refining ladle by blowing inert gas through a rotating impeller. For purposes modelling, plexiglass model scale 1:1 is used for operating ladle. Part hollow shaft supply that equipped an impeller and two baffles. melt simulated at decrease dissolved oxygen liquid (water). This aimed evalua...

In the present paper, time dependent creep behavior of hollow circular rotating cylinders made of exponentially graded material (EGM) is investigated. Loading is composed of an internal pressure, a distributed temperature field due to steady state heat conduction with convective boundary condition and a centrifugal body force. All the material properties are assumed to be exponentially graded a...

We study electromagnetic plane wave diffraction by a hollow circular cone with thin walls modelled by the so-called impedance-sheet boundary conditions. By means of Kontorovich–Lebedev integral representations for the Debye potentials and a ‘partial’ separation of variables, the problem is reduced to coupled functional difference (FD) equations for the relevant spectral functions. For a circula...

Closed-form expressions for the Cauchy stress, microstress, moment-stress, and the torque-twist relationship in a twisted hollow circular tube are derived for a rigid-plastic strain-gradient plasticity. This is accomplished for any of the gradient-enhanced effective plastic strain measures from a considered broad class of these measures. Numerical results are given and discussed for the two mos...

Several numerical and analytical models have been used to study underwater acoustics problems. The most accurate and realistic models are usually based on the solution of the wave equation using a variety of methods. Here, a hybrid numerical-analytical model is proposed to address the problem of underwater sound scattering by an elastic shell structure, which is assumed to be circular and that ...