The higher pollutant level in non premixed combustion and safety issues pertaining to can be counteracted by partially-premixed mode of combustion. partially flames (PPF) exhibit the benefits both flames. PPF enhances complete leading reduced soot formation hence lower emission. However, equivalence ratio plays an important role stability such This paper reports experimental investigation on fl...

The generation and turbulent transport of temporal equivalence ratio fluctuations in a swirl combustor are experimentally investigated compared to one-dimensional model. These generated by acoustic perturbations at the fuel injector play crucial role feedback loop leading thermoacoustic instabilities. focus this investigation lies on interplay between coherent vortical structures that both affe...

The paper reviews striking features of swirling flows—collapse, swirl generation, vortex breakdown, hysteresis, and axisymmetry breaking—and the mechanisms involved with the help of conical similarity solutions of the Navier-Stokes equations. The strong accumulation of axial and angular momenta, observed in tornadoes and flows over delta wings, corresponds to collapse, i.e. the singularity deve...

One-dimensional stability analysis of a hydraulic system composed of a penstock, a runner, and a draft tube was carried out to determine the cause of the full load draft tube surge. It is assumed that the cavity volume at the runner exit is a function of the pressure at the vortex core evaluated from the instantaneous local pressure at the runner exit and an additional pressure decrease due to ...

Auroral brightness and color ratio imagery, captured using the Juno mission's Ultraviolet Spectrograph, display intense emissions poleward of Jupiter's northern main emission, these are split into two distinctly different spectral or “color ratio” regimes. The most region, designated “swirl region” by Grodent et al. (2003), https://doi.org/10.1029/2003ja010017, exhibits a high ratio, while low ...

A 32-year-old woman (gravida 2, para 2) presented with severe, midepigastric abdominal pain that began 3 hours after delivery. Her surgical history was significant for laparoscopic Roux-en-Y gastric bypass (LRYGB) 4 years earlier. An axial computed tomographic (CT) image of the abdomen depicted twisting of central mesentery and origin of the “swirl” (image A, arrow). A coronal CT image of the a...

Rayleigh scattering temperature measurements were obtained in a turbulent reactive swirling coaxial jet discharged from a swirl-stabilized burner along the jet-flame centerline. They are reported up to 10 fuel nozzle diameters downstream of the burner exit at a Reynolds number of 29000. The effect of swirl numbers (S=0.3, 0.58, 1.07) on the temperature fields, the power spectral density of temp...

Recent experiments on particle diffusion in bacterial baths indicate the formation of correlated structures in the form of bacterial swirls. Here we predict that such a structural ordering would give rise to the new effect of propagating shear waves in a bacterial bath at length scales of the order of a swirl, which corresponds to time scales of the order of the lifetime of a swirl. Our predict...

Ammonia has been proposed as a potential energy storage medium in the transition towards a lowcarbon economy. This paper details experimental results and numerical calculations obtained to progress towards optimisation of fuel injection and fluidic stabilisation in swirl burners with ammonia as the primary fuel. A generic tangential swirl burner has been employed to determine flame stability an...

Simultaneous planar laser-induced incandescence, hydroxyl radical planar laser-induced fluorescence, and droplet Mie scattering are used to study the instantaneous flame structure and soot formation process in an atmospheric pressure, swirl-stabilized, liquid-fueled, model gas-turbine combustor. Optimal excitation and detection schemes to maximize single-shot signals and avoid interferences fro...