• Ratul Das

In gravel bed streams, the turbulent flow characteristics are strongly influenced by the non-homogeneity of the bed topography. The time-averaged flow characteristics close to the bed are spatially heterogeneous. To overcome this, conceptually the time averaging of Navier-Stokes equations are supplemented by spatial area averaging in the plane parallel to the average bed. To study the spatially-averaged (SA) turbulence characteristics in flows over a gravel bed, a uniform flow is created over the bed. Nortek’s Vectrino four-receiver Acoustic Doppler velocimeter (ADV) probe was used to measure the instantaneous three-dimensional velocity components at the groove. Velocity distributions below the roughness crest level fairly matches with a third-degree polynomial series. In the near-bed region the Reynolds shear stresses (RSS) undergo a damping because of a diminishing level of turbulence.

Gravel bed streams, Turbulent flow, Acoustic Doppler velocimeter, Reynolds shear stress

"Estimation of Turbulent Shear stress in Gravel- bed streams: An Experimental Study", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 5, page no.281-283, May 2019, Available :http://www.jetir.org/papers/JETIRCU06056.pdf

"Estimation of Turbulent Shear stress in Gravel- bed streams: An Experimental Study", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 5, page no. pp281-283, May 2019, Available at : http://www.jetir.org/papers/JETIRCU06056.pdf