Analyzing Shear Velocity for Sediment Grain Exposed to Fluid Drag

How can we calculate the shear velocity for a sediment grain exposed to fluid drag?

Given the sediment grain size is 0.25mm and located at a distance of 74mm from the channel bed.

Calculating Shear Velocity for Sediment Grain

To calculate the shear velocity for a sediment grain exposed to fluid drag, we can utilize the Shields parameter. The Shields parameter is a key factor that relates the shear stress, grain size, and fluid properties. By following the steps below, we can determine the shear velocity for the given sediment grain:

Shear Velocity Calculation Process

In order to determine the shear velocity for the sediment grain, we need to follow these steps:

1. Convert Units: Convert the sediment grain size and distance from the channel bed to meters. Given that the sediment grain size is 0.25mm and the distance from the channel bed is 74mm, we have 0.25mm = 0.00025m and 74mm = 0.074m.

2. Calculate Shields Parameter: Use the Shields parameter equation: θ = τ / (ρ * g * d), where θ is the Shields parameter, τ is the shear stress, ρ is the fluid density, g is the acceleration due to gravity, and d is the sediment grain size.

3. Solve for Shear Velocity: Rearrange the equation to solve for shear stress, τ = θ * (ρ * g * d), and substitute the known values to calculate the shear velocity.

By following these steps and understanding the relationship between shear stress, sediment grain size, and fluid properties, we can accurately determine the shear velocity for the sediment grain exposed to fluid drag.