Simultaneous three-dimensional measurement of temperature and velocity fields in swirling combustion

Simultaneous measurement and visualisation of multi-parameters are crucial in understanding and characterising complex combustion. A measurement technique coupled with deflection tomography and particle image velocimetry was proposed to obtain three-dimensional temperature and velocity fields of swirling combustion. A combustion system was developed to generate a non-premixed swirling flame. Moirepatterns in four view angles and tracer particle images illuminated by volume light source were captured simultaneously using a hybrid measurement system. Three-dimensional temperature and velocity fields were quantitatively reconstructed. The characteristics of swirling combustion were analysed on the bases of visualisations of temperature distribution, velocity distribution, streamlines. In each cross-section with varying heights from the nozzle, the high velocity and high temperature areas showed similar closed or semi-closed annular structure. In the central longitudinal section, the V-shaped high temperature and high velocity regions showed the swirling structure of combustion flow field. The high temperature area did not coincide with the high velocity area but was located relatively downstream. Additionally, the high velocity area was in the periphery of the high temperature area.