الفهرس 
aAssessment of K-KL-} model application to oscillatory pipe flow
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Abstract
The three-equation eddy-viscosity model k-kl-} RANS modeldeveloped by Walters and Cokljat (Walters and Cokljat, 2008) for stationary transitional flows is considered in the present numerical simulation of oscillating pipe flow.ANSYS FLUENT finite-volume solver is used, which enables the introduction of the oscillating pressure gradient as a source term in the governing equation. The fully-developed turbulent flow is first considered and the numerical results are compared with reported experimental data and DNS values (Eggels et al, 1994). Accordingly, the model constant C_}1that corresponds to the turbulent production term is adjusted to0.533replacing its original value of 0.44 for unbounded shear flows. The analytically-resolved oscillating laminar flow problem is next considered as limiting casesfor validation purposes. The resulting instantaneous velocity profiles show excellent agreement with theory. The simulation runs are further extended to transitional oscillating flow at Womeresley numbers of 5, 13 and 26. As anticipated, transition to turbulence is noticed within the deceleration phase, followed by a re-laminarization phase.The present numerical results show good agreement with available DNS profiles within the inner-wall regimesr^+{u2264}100, whereas some deviations are noticed within the outer wake regimes