Tomographic reconstruction of the instantaneous 3D chemiluminescence field of a highly turbulent swirl-stabilised flame

 

DNS of the Cambridge stratified burner

Axial velocity component (U) from the 1.6 billion cell DNS of the Cambridge stratified burner.

DNS of the Cambridge stratified burner

Mixture fraction (F) from the 1.6 billion cell DNS of the Cambridge stratified burner.

LES of pulverized coal combustion in a large-scale laboratory furnace

The picture shows coal particles coloured by temperature [K] and with
size scaled to the diameter. The computational domain is 1200 mm long and has a
width of 600 mm. Particles are injected at room temperature and are decelerated in
the internal recirculation zone until eventually reverse their direction of
movement. As particles heat and combustion proceeds the diameter of the particles
decreases.

  Combustion progress in a 4-valve engine, during the power stroke.

 Progress variable source term in a 4-valve engine, during the power stroke.

Pulverized coal combustion

Illustration of oxygen mass fraction in the mid axial section of a large-scale laboratory furnace (diameter = 600 mm).

  Mixture fraction in a 4-valve engine, during the intake stroke.

Sydney swirl flame

Illustration of OH.

LES of  high frequency  thermoacoustic in a generic combustion chamber

To study the high frequency thermoacoustic a generic combustor is designed, which shows the first radial mode with the frequency of almost 6 kHz. The movie illustrates the phased avarage pressure oscillation in the combustion chamber.

Pulsed-Jet

A single pulse of a gas-jet is investigated to improve the insights into the injection process in direct­-injection internal combustion engines. The jet investigated here consists of a tracer gas only, to investigate the fluid dynamics of jet break up, the evolution of turbulence, and jet impingement on the wall. The simulation was performed with the inhouse PsiPhi code, using a grid of 1,000,000,000 finite volumes, distributed on 1,000 cores of the CCSS Cray. The simulation is based on the Large-Eddy Simulation approach, where the effect of small turbulent structures (eddies), that can no longer be resolved by the computational grid, is modelled through a turbulent viscosity that represents the enhanced momentum exchange due to turbulence.
Reference: To be presented (poster) at the 2012 International Symposium on Combustion.

Sydney Bluff-Body Flame

A Large-Eddy Simulation of the Sydney Bluff Body flame has been conducted using the inhouse flowsi code. A steady flamelet model was used to calculate the chemical state. The visualisation shows an instantaneous snapshot of the temperature field in the central plane.
Kempf, A., Lindstedt, R.P., and Janicka, J. (2006) LES of a bluff-body stabilised non-premixed flame. Combust. Flame, 144, 170–189.

Darmstadt Stratified Flame

A Large-Eddy Simulation of the Darmstadt Stratified flame has been conducted using the inhouse PsiPhi code with 70 million cells (every pixel corresponds to a cell). The image is a compound of the mixture fraction field (yellow) and the progress variable field (blue), the hot combustion products are shown in white.
Reference: Cavallo Marincola, Navarro, Ma, Kempf (Symposium 2012), ...

Flat flame in low pressure reactor

Comparison between the measured and the computed temperature of the investigated flame. Left: Temperature field (without HMDSO) of the reactor. Right top: temperature (without HMDSO) along the centerline as a function of HAB. Right bottom: enlarged zone form 0 to 45 mm HAB for the temperature of flame doped with varied HMDSO concentration.

Pulsed-Jet

A single pulse of a gas-jet is investigated to improve the insights into the injection process in direct­-injection internal combustion engines. The jet investigated here consists of a tracer gas only, to investigate the fluid dynamics of jet break up, the evolution of turbulence, and jet impingement on the wall. The simulation was performed with the inhouse PsiPhi code, using a grid of 1,000,000,000 finite volumes, distributed on 1,000 cores of the CCSS Cray. The simulation is based on the Large-Eddy Simulation approach, where the effect of small turbulent structures (eddies), that can no longer be resolved by the computational grid, is modelled through a turbulent viscosity that represents the enhanced momentum exchange due to turbulence.
Reference: To be presented (poster) at the 2012 International Symposium on Combustion.

 

Cambridge Stratified Flame

The image shows a cross section through the progress variable field inside the Cambridge bluff body, calculated by LES. The inhouse PsiPhi code was used in combination with a Flame Surface Density approach and a mixture fraction dependent laminar flame speed. A total of over 100 million cells was used for this simulation (every pixel corresponds to a cell).
Reference: To be presented at the 2012 Workshop on Turbulent Non-Premixed Flames.