the objective of this study was to examine the effects of the fluidized-bed drying me-thod on the final quality of two varieties of iranian rice, medium- and long grain. the re-sults were compared to that of paddy drying using a traditional method. rough rice was treated in the fluidized bed drier at 140ºc for 2 minutes. similar samples were dried for 8-10 hrs by the traditional method. dried s...

density or gravity currents have been always one of the main causes for sedimentation along many of the dam reservoirs. so controlling this phenomenon is very important for increasing useful life of such reservoirs. in this research study the effect of a combination of rough bed and obstacle on the control of sedimentary density current has been investigated. experiments were conducted in a til...

Density or gravity currents have been always one of the main causes for sedimentation along many of the dam reservoirs. So controlling this phenomenon is very important for increasing useful life of such reservoirs. In this research study the effect of a combination of rough bed and obstacle on the control of sedimentary density current has been investigated. Experiments were conducted in a til...

Large-eddy simulations (LES) of the flow over a non-uniformly roughened channel bed are carried out to study the effect of non-uniform bed roughness on turbulence driven secondary currents and turbulence statistics. The channel bed is comprised of alternating rough and smooth strips, the width of which corresponds to the water depth. The Reynolds number based on hydraulic radius and bulk veloci...

The hydraulics of steep mountain streams differ from lower gradient rivers due to shallow and rough flows, energetic subsurface flow, and macro-scale form drag from immobile boulders and channel and bed forms. Heightened flow resistance and reduced sediment transport rates in steep streams are commonly attributed to macro-scale form drag; however, little work has explored steep river hydrodynam...

An experimental study with four different types of bed conditions was carried out to understand the effect of roughness in open channel flow at two different Reynolds numbers. The bed conditions include a smooth surface and three different roughness conditions, which were generated using sand grains with a median diameter of 2.46 mm. The three rough conditions include a surface with distributed...

Intermittent drying is a satisfactory technique for drying of heat sensitive grains especially rough rice. This method consists of two separate stages applied intermittently: drying and tempering. In this work, intermittent drying of rough rice is investigated both theoretically and experimentally. In order to characterize this process; a multi-scale model consisting of macroscopic and microsco...

A numerical model based on the smoothed particle hydrodynamics method is developed to simulate depth-limited turbulent open channel flows over hydraulically rough beds. The 2D Lagrangian form of the Navier-Stokes equations is solved, in which a drag-based formulation is used based on an effective roughness zone near the bed to account for the roughness effect of bed spheres and an improved sub-...