in the present study the effect of curvature ratio and coil pitch for tio2/water nanofluid laminar flow on heat transfer behavior and pressure drop through helical coils with different geometries was investigated experimentally. the tio2/water nanofluids at 0.25% to 2% particle volume concentrations have been prepared by using a two-step method. the experiments were performed for coils with cur...

helical coil heat exchangers are widely used in industrial applications ranging fromcryogenic processes, air-conditioning, and nuclear reactors to waste heat recovery due totheir compact size and high heat transfer coefficient. in this kind of heat exchangers, flowand heat transfer are complicated. this paper reports a numerical investigation of theinfluence of different parameters such as coil...

Parallel tubular channel angular pressing (PTCAP) process is a novel recently developed severe plastic deformation technique for fabrication of ultrafine grained (UFG) metallic tubes. This new process consists of two half cycles and is affected by several parameters such as channel angles, deformation ratio and curvature angles. In this paper, the effects of these parameters on the plastic defo...

methods are proposed to develop idealized moment-curvature response curves of slender rectangular rc wall sections with uniformly distributed longitudinal reinforcement, using limit states, namely, cracking of concrete in tension, tensile yielding of reinforcement layers, and compression failure of concrete. it is recommended that tensile yielding of an inner layer of reinforcement is considere...

This paper presents a numerical study of local mass transfer coefficients in a 90° bend using the RNG version of k–e model to include the influence of curvature on the turbulent transport. Simulations were performed for flow through a 90°, 3-D bend for Reynolds numbers of 13500, 90000, and 390000, Schmidt numbers of 2.53 and 700 and curvature ratios of 1.5, 2, and 2.5. The differences betwe...

this paper presents a numerical study of local mass transfer coefficients in a 90° bend using the rng version of k–e model to include the influence of curvature on the turbulent transport. simulations were performed for flow through a 90°, 3-d bend for reynolds numbers of 13500, 90000, and 390000, schmidt numbers of 2.53 and 700 and curvature ratios of 1.5, 2, and 2.5. the differences between t...

agricultural sector experiences the application of automated systems since two decades ago. these systems are applied to harvest fruits in agriculture. computer vision is one of the technologies that are most widely used in food industries and agriculture. in this paper, an automated system based on computer vision for harvesting greenhouse tomatoes is presented. a ccd camera takes images from ...

in this paper, the time-like hyperruled surfaces in the minkowski 4-space and their algebraicinvariants are worked. also some characteristic results are found about these algebraic invariants.