Heat exchangers are widely used in power engineering and industrial applications, many techniques such as coiled tube, surface tension devices, rough surfaces, extended surfaces have been investigated to enhancethermal performance and to minimize the cost and size of the heat exchanger equipment. One of the most important techniques is tube insert. In general,tube inserts can be classified into...

Using Donnell-type shell theory a simple and exact procedure is presented for linear buckling analysis of functionally graded conical shells under axial compressive loads and external pressure. The solution is in the form of a power series in terms of a particularly convenient coordinate system. By analyzing the buckling of a series of conical shells, under various boundary conditions and diffe...

Abstract— The main aim of this study was to control the nonlinear process using multi-model PI controller. A multi model is developed for conical tank and it is validated against the real time setup conical tank process. A Multi model based PI controller is also developed, and implemented with realtime setup, and their performances are compared with that of the conventional controller of real t...

Drawing of square section rod from round bar can be done with two die shapes. In the first die shape, deformation starts from corners of the square and in second die shape, deformation starts from sides of square. This article has compared the drawing force for both die shapes and as a result optimum die shape was determined. Due to complexity of metal flow inside the die, analyzing of actual p...

one of the effective methods to improve the thermal efficiency of solar collectors is using nanofluids as the coolant. the present study experimentally investigated the effect of sio2/water nanofluid with 1% mass fraction on the performance of a symmetric collector, i.e. conical solar collector. the conical solar collector with 1 m2 area and normal to the earth was tested in ahvaz, a city in th...

In Shark Bay, Western Australia, bottlenose dolphins Tursiops sp. carry conical sponges Echinodictyum mesenterinum on their rostra in the only documented cetacean foraging behaviour using a tool (‘sponging’). In this study, we examined the influence of various ecological factors on live sponge distribution and the occurrence of sponging in parts of the western gulf of Shark Bay. We assessed spo...

The existing formula for the transfer matrix of conical elements assumes constant wave number, which is only valid for sufficiently short conical elements. In acoustic waveguides, the phase velocity, attenuation constant, and hence complex wave number depend on frequency and cross-section radius. As for conical waveguides, the cross-section radius is position dependent, the transfer matrix must...

the output of a piezoelectric nanogenerator based on zno nanowire is largely affected by the shape of nanowire. in order to obtain mechanically stable nanogenerator with high performance, the investigation of mechanical and electrical characteristics related to the nanowires and materials used in nanogenerators are of great interest and significance. this paper presents the various behavior of ...

the geometry of a collector is one of the important factors that can increase the incident radiation on the collector surface. in the present study, the incident radiation for a stationary collector with cone geometry, i.e. a conical collector, is theoretically and experimentally investigated. this type of collector is always stable and does not need a fixture to install. moreover, it has a sym...