Sediment Transport: Difference between revisions

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The current-related suspended load transport with wave stirring is given by
The current-related suspended load transport with wave stirring is given by
{{Equation|<math> \frac{q_s}{\sqrt{ (s-1) g d^3 }} = U c_R \frac{\epsilon}{w_s} \biggl[ 1 - \exp{ \biggl( - \frac{w_s d}{\epsilon}} \biggr) \biggr] </math>|2=2}}
{{Equation|<math> \frac{q_s}{\sqrt{ (s-1) g d^3 }} = U c_R \frac{\epsilon}{w_s} \biggl[ 1 - \exp{ \biggl( - \frac{w_s d}{\epsilon}} \biggr) \biggr] </math>|2=2}}
The reference sediment concentration is obtained from
{{Equation|<math> c_R = A_{cR}  \exp{ \biggl( - 4.5 \frac{\theta_{cr}}{\theta_{cw}}}  \biggr)  </math>|2=3}}
where the coefficient <math>A_{cR}</math> is given by
{{Equation|<math> A_{cR} = 3.5x10^3 \exp{ \bigl( - 0.3 d_{*} } \bigr)  </math>|2=4}}
with <math> d_{*} = \sqrt{(s-1) g \ mu^2} d </math> being the dimensionless grain size and <math> \mu </math> the kinematic viscosity of water.
The sediment mixing coefficient is calculated as
{{Equation|<math> \epsilon = \biggl( frac{k_b^3 D_b + k_c^3 D_c + k_w^3 D_w}{\rho} \biggr)  </math>|2=5}}


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Revision as of 21:54, 15 October 2010

Lund-CIRP Transport Equations

Camenen and Larson (2005, 2007, and 2008) developed a general sediment transport formula for bed and suspended load under combined waves and currents.

Bed load

The current-related bed load transport with wave stirring is given by

  qb(s1)gd3=acθcθcwexp(bcθcrθcw) (1)

Suspended load

The current-related suspended load transport with wave stirring is given by

  qs(s1)gd3=UcRϵws[1exp(wsdϵ)] (2)

The reference sediment concentration is obtained from

  cR=AcRexp(4.5θcrθcw) (3)

where the coefficient AcR is given by

  AcR=3.5x103exp(0.3d*) (4)

with d*=(s1)g mu2d being the dimensionless grain size and μ the kinematic viscosity of water.

The sediment mixing coefficient is calculated as

  ϵ=(frackb3Db+kc3Dc+kw3Dwρ) (5)
Symbol Description Units
qbc Bed load transport rate m3/s
s Relative density m
θc Shields parameter due to currents -
θcw Shields parameter due to waves and currents -
θcw Critical shields parameter -
ac Empirical coefficient -
bc Empirical coefficient -