D. M. Markovich

Diagnostics of jet flows by using tomographic particle image velocimetry

A modern method of velocity measurement in a flow volume on the basis of few-projections optical tomography and correlation of moving particles is considered. The method is used to measure instantaneous three-dimensional velocity distributions in non-swirling and swirling turbulent jet flows. In addition to measurement of three-dimensional velocity distributions, specific features of this experiment are a larger depth of the measurement region (up to 40 mm) and a higher resolution of cameras (up to 4 MP as compared to previous authors’ tomographic measurements). To verify the correctness of tomographic measurements, the velocity in the plane passing along the jet axis is measured by the Stereo PIV method. The difference between the stereoscopic and tomographic measurements of three components of the mean velocity for the flows considered in this study is smaller than 10%. A three-dimensional vortex structure of the core of a swirling jet is visualized with a spatial resolution of 3 mm.

High-speed imaging of cavitation regimes on a round-leading-edge flat plate and NACA0015 hydrofoil

Graphical abstract

Application of modern optical methods for detecting the spatial structure of turbulent flames

A number of modern optical methods used for diagnostics of reactive flows are described. Various aspects of using advanced modifications of particle image velocimetry (Stereo-PIV, High-repetition PIV, and Tomo-PIV) for measuring instantaneous velocity fields in reactive flows are discussed in detail. Capabilities of PIV and spectroscopy of flame radiation (CH* radical) in obtaining data on the spatial flow structure and the flame are demonstrated by an example of studying a swirled turbulent propane-air flame and an isothermal jet.

Physical and Mathematical Simulation of Aerodynamics and Combustion in the Furnace Chambers of Power Installations

The possibilities of studying flows and heat transfer in various power installations using dedicated computer programs developed at the Institute of Thermal Physics, Siberian Branch of the Russian Academy of Sciences are shown. The results obtained from studies of processes in furnace chambers carried out on the experimental models of E-500 and P-67 boilers are presented.

Experimental and numerical simulation for swirl flow in a combustor

Results of the experimental and numerical simulation for swirl flow in combustion of a lean methane-air mixture in a model combustor at atmospheric pressure are represented. The panoramic method for the flow velocity measurement and the calculation by a large eddy method were used for the investigation of the nonstationary turbulent flow. The numerical modeling for the breakdown of the vortex core of the flow and the topology of large-scale vortex structures forming in it showed the close fit to the experiment. The analysis of obtained data showed that for the case of the intensive swirl of the flow as well as in the case of the flow without combustion, dynamics of the flow with combustion was determined by the global azimuthal instability mode corresponding to the intensive precession of the vortex core. The flame had the similar characteristics of the stability and compactness in the case of stabilization by the low swirl; however, velocity pulsations in the flow corresponded to the development of only local instability modes. Thus, the other kind of vortex breakdown in the case of the low swirl, for which the central recirculation zone is lacking, is not only favorable in view of the reduction of the NOx emission, but also remains a possibility for the effective use of the active control method for the flow and combustion. In particular, the given result may be used for the elimination of the thermoacoustic resonance in combustors.