Acoustic field generated by a single vortex approaching a hydrofoil is studied. A combined vortex/RANS simulation for the near–field unsteady vorticity is developed to include effects from RANS Reynolds stresses. The far-field acoustics is calculated using a vortex sound formula with the near-field vorticity as the source. The results show that at a higher incident angle when the RANS shows a s...

The objective of this study is to evaluate a recently proposed dynamic hybrid Reynoldsaveraged Navier-Stokes (RANS)-Large Eddy Simulation (LES) modeling framework that seeks to effectively address issues regarding RANS-to-LES transition and explicit grid dependence inherent in most current hybrid RANS-LES (HRL) models. RANSto-LES transition in the investigated dynamic HRL (DHRL) model is based ...

In this paper, we study the distribution of distances in random Apollonian network structures (RANS), a family of graphs which has a one-to-one correspondence with planar ternary trees. Using multivariate generating functions that express all information on distances, and singularity analysis for evaluating the coefficients of these functions, we prove a Rayleigh limit distribution for distance...

[1] In this paper we consider the problem of modeling a turbulent pulsating boundary layer over ripples. We compare the results of two modeling strategies, Wilcox’s k w Reynolds-Averaged Navier-Stokes equations (RANS) and large-eddy simulation (LES) employing the Lagrangian dynamic eddy viscosity model. The geometry and parameters employed are relevant to nearshore oceanic flows, and the result...

Diverse arrays of modern applications require accurate predictions of complex turbulent flows. These range from flows across aircraft and inside turbomachinery, over the planet for weather prediction and through the heart for cardiac auscultation, etc. Due to the disparate character of these complex flows, predictive methods must be robust so as to be applicable for most of these cases, yet pos...

We discuss the development of a simplified model for the jet noise source that can be used in practical predictions of installed noise. In the proposed scheme, the source is prescribed on a radiator surface defining the boundary between the inner rotational jet flow and the outer linear pressure field. The source consists of wavepacket-type partial fields whose noise propagation can be computed...

The primary objective of this study is to evaluate the accuracy of using computational fluid dynamics (CFD) turbulence models to predict entropy generation rates in bypass transitional boundary layers flows under zero and adverse pressure gradients. Entropy generation rates in such flows are evaluated employing the commercial CFD software, ANSYS FLUENT. Various turbulence and transitional model...

Predictions of the flow over a wall-mounted hump are obtained using solutions of the Reynolds-averaged Navier-Stokes (RANS) equations and Detached-Eddy Simulation (DES). The upstream solution is characterized by a two-dimensional turbulent boundary layer with a thickness approximately half of the maximum hump thickness measured at a location about two chord lengths upstream of the leading edge....

A novel penalized wall function method for simulations of wall-bounded compressible turbulent flows is proposed. The new approach based on the Reynolds-averaged Navier–Stokes (RANS) equations to model outer region boundary layer, while inner part approximated by equilibrium model. differential formulation match external and solutions reformulated in a form generalized characteristic-based volum...

Historically mobile Radio Access Networks (RANs) were optimised initially to maximise coverage and subsequently to improve capacity, user data rates and quality of service. However, the recent exponential growth in the volume of transmitted data coupled with the ever increasing energy costs has highlighted the need to optimise futuristic RANs from an energy efficiency perspective. This research...