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...

Velocities are measured using LDA within the bottom boundary layer for 10 oscillatory flow tunnel experiments involving regular and amplitude modulated flows over a gravel-rough bed sand-rough bed. Corresponding were equivalent in terms of rms velocity, period, skewness asymmetry. The experimental results compared with predictions based on 1DV RANS model k?? turbulence closure. effects modulati...

Present study examines turbulent structures of a rough bed open-channel flow in the context of deterministic approach. Instantaneous velocity field is measured in different hydraulic conditions using two dimensional Particle Image Velocimetry (PIV) in vertical plane and Stereoscopic PIV in horizontal plane. Different techniques and quantities such as swirl strength, two-point and cross-correlat...

To reproduce the natural flow topography in a laboratory environment, it is crucial to recapture its bed condition in order to ensure the accurate representation. Water-worked bed represents a state-of-the-art experimentally formed bed to imitate the natural-formed channel in most rivers or natural streams. Recently, this technique has been intensively studied through experimental and computati...

[1] Steep, rough channels occupy a large fraction of the total channel length in mountainous regions. Most sediment mobilized on hillslopes must pass through these streams before reaching lower-gradient channels. Steep channels have wide grain size distributions that are composed of finer, more mobile sediment and large, rarely mobile grains. The large grains can bear a significant portion of t...

We present the velocity profile measured within a porous bed below rough turbulent open channel flow. Mean streamwise velocity has a minimum in the top pore, just below the bed surface, and then increases towards a constant value in the deeper pores. We argue that the velocity minimum in the top pore is due to enhanced turbulence generated within the external flow. This produces a flow regime s...

The effect of bed roughness on an iso-kinetic chemical plume released into the logarithmic region of the bed boundary layer of an open channel flow is examined. The bed roughness is varied systematically to generate flows in the smooth (painted polyethylene sheets), transitional rough (2.5-mm and 11.5-mm gravel beds), and fully rough (21.0-mm gravel bed) regimes. Concentration fields are measur...