A Physically Based Stochastic Boundary Layer Perturbation Scheme. Part II: Perturbation Growth within a Superensemble Framework

A NOVEL HOMOTOPY PERTURBATION METHOD: KOUROSH´S METHOD FOR A THERMAL BOUNDARY LAYER IN A SATURATED POROUS MEDIUM

this paper a novel homotopy perturbation method has been presented for forced convection boundary layer problems in a porous medium. Noting the infinite condition, a homotopy form which is similar to the singular perturbation form has been considered. The inner and outer solutions have been achieved and the coincidence of the results has been investigated with a proper matching method. The resu...

Qualitative Symbolic Perturbation: a new geometry-based perturbation framework

In the literature, the generic way to address degeneracies in computational geometry is the Symbolic Perturbation paradigm: the input is made dependent of some parameter ε so that for ε positive and close to zero, the input is close to the original input, while at the same time, in non-degenerate position. A geometric predicate can usually be seen as the sign of some function of the input. In t...

Perturbation Growth and Structure in Uncertain Flows. Part II

Perturbation growth in uncertain systems associated with fluid flow is examined concentrating on deriving, solving, and interpreting equations governing the ensemble mean covariance. Covariance evolution equations are obtained for fluctuating operators and illustrative physical examples are solved. Stability boundaries are obtained constructively in terms of the amplitude and structure of opera...

Dynamic roughness perturbation of a turbulent boundary layer

The zero-pressure-gradient turbulent boundary layer over a flat plate was perturbed by a temporally oscillating, spatial impulse of roughness, and the downstream response of the flow field was interrogated by hot-wire anemometry and particleimage velocimetry. The key features common to impulsively perturbed boundary layers, as identified in Jacobi & McKeon (J. Fluid Mech., 2011), were investiga...

Study of Boundary Layer Convective Heat Transfer with Low Pressure Gradient Over a Flat Plate Via He’s Homotopy Perturbation Method