English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The turbulent flow past a wall-mounted square cylinder with an aspect ratioof four was investigated with the aid of Spalart-Allmaras improved delayeddetached-eddy simulation (S-A IDDES) and proper orthogonal decomposition (POD).The Reynolds number was equal to 12,000 (based on the free-stream velocity andobstacle width). This study focused on analysing the vortical structure of thewake and vortex shedding process along the obstacle height. A quantitativecomparison of the first and second-order flow statistics with the availableexperimental and direct numerical simulation data was used to validate thenumerical results. The numerical model coupled with the vortex method (VM) ofgenerating the turbulent inflow conditions could successfully reproduce theflow field around and behind the obstacle with commendable accuracy. The flowstructure and vortex shedding characteristics near the wake formation regionhave been discussed in detail using time-averaged and instantaneous flowparameters obtained from the simulation. Dipole type mean streamwise vortex andhalf-loop hairpin instantaneous vortices with energetic motions wereidentified. A coherent shedding structure was reported along the obstacle usingtwo-point correlations. Two types of vortex shedding intervals were identified,namely, low amplitude fluctuations (LAFs) and high amplitude fluctuations(HAFs). The POD analysis of the wake showed that for the elevations between0.25 to 0.5 of the obstacle height, the first two POD modes represent thealternating shedding and the contribution to the kinetic energy is between66.6% to 57.6%. A simple low-order model based on the vortex-shedding phaseangle and the spectrum of the time coefficients obtained from POD was developedto predict the wake dynamics at the range of elevations where the alternatingshedding is dominated.

On the characteristics of the turbulent wake behind a wall-mounted square cylinder