The editors have assembled a world-class group of contributors who address the questions the combustion diagnostic community faces. They are chemists who identify the species to be measured and the interfering substances that may be present; physicists, who push the limits of laser spectroscopy and laser devices and who conceive suitable measuremen

Applied Combustion Diagnostics

Principles of non-intrusive diagnostic techniques and their applications for fundamental studies of combustion instabilities in gas turbine combustors: A brief review

Aviation kerosene is commonly used in combustion and regenerative engine cooling processes in propulsion and power-generation systems, including rocket, scramjet, and advanced gas turbine engines. In this paper, many surrogate models proposed in the open literature are examined for their applicability and accuracy in calculating thermodynamic and transport properties of the China aviation kerosene RP-3 at supercritical pressures, based on the extended corresponding-states methods. The enthalpy change from endothermic decomposition and low heating value from combustion of the jet fuel are also evaluated. Results from a number of simple and representative surrogate models, which contain species components ranging from 1 to 10, are analyzed in detail. Data analyses indicate that a surrogate model with four species is the best choice for thermophysical property calculations under the tested conditions, with fluid temperature up to 650 K at various supercritical pressures. The surrogate model is particularly accurate in predicting the pseudo-critical temperature of aviation kerosene RP-3 at a supercritical pressure. A simple surrogate model containing the n-decane species and a surrogate model containing 10 species are the other two acceptable options. The work conducted herein is of practical importance for theoretical analyses and numerical simulations of various physicochemical processes at engine operating conditions.

Analyses of surrogate models for calculating thermophysical properties of aviation kerosene RP-3 at supercritical pressures

An investigation of air-swirl design criteria for gas turbine combustors through a multi-objective CFD optimization

This paper has focused on the droplets behavior of kerosene RP-3 spray produced by a pressure swirl atomizers in terms of spray pattern, droplet size spatial distribution, mean droplet size, and distribution index with variations of pressure differential. The analyses have been carried out experimentally with the aid of optical diagnostic methods. The spray pattern, such as spray cone angle and fuel spatial distribution, has been measured by the technique of planar laser induced fluorescence of kerosene. A method for correction of fuel distribution measurement error induced by laser attenuation in spray is proposed and validated. The droplet size spatial distribution in central axis plane of the spray has been measured by a planar droplet sizing method which combining laser induced fluorescence and Mie scattering. The spray pattern in axial center plane and cross-sectional plane perpendicular to axis of the atomizer indicate that the droplets in spray concentrate around the outer periphery and in a narrow annular zone at the near-field of fuel injector exit, and then disperse to produce a solid spray at downstream of the spray. The analyses of droplet size spatial distribution, Sauter mean diameter, and distribution index with pressure differential clearly show the presence of droplets collision and its adverse effects on droplet size uniformity. The spray outline, droplet mass spatial distribution, and droplet size spatial distribution, droplets dispersion and collision in the process of atomization provide a great insight into the processes of atomization and spray development, which are key information for fuel injector design and quality control. The visualizations of spray pattern and droplet size spatial distribution with variations of pressure differential for pressure swirl atomizer are key issues in swirl cup or internally staged airblast fuel injectors because pressure swirl atomizer provides primary atomization or pilot spray which affects the quality of air/fuel mixing in lean-burn combustion. Moreover, a well-defined and complete database regarding the isothermal hollow cone spray is provided for validation of spray model.

Experimental investigations of spray generated by a pressure swirl atomizer

Investigations of the effects of spray characteristics on the flame pattern and combustion stability of a swirl-cup combustor

Experimental Investigation of Spray and Combustion Performances of a Fuel-Staged Low Emission Combustor: Part I — Effects of Main Swirl Angle

The invention discloses a low-pollution combustion chamber adopting fuel-grading and three-stage cyclone air inlet. The low-pollution combustion chamber comprises an on-duty oil supply nozzle, a primary-combustion oil supply nozzle, three-stage cyclones and a flame tube. Fuel is respectively provided for the on-duty oil supply nozzle and the primary-combustion oil supply nozzle in two ways, and the three-stage coaxial cyclones supply air to the head of a combustion chamber. The two stages of cyclones on the inner side of the combustion chamber refer to an oblique-cutting hole cyclone and a radial cyclone, cyclone of the two-stage cyclones are in opposite directions. A centrifugal atomizing nozzle is arranged at the center of the oblique-cutting hole cyclone, and the second-stage cyclone on the inner side are combined and matched with a center on-duty nozzle. The cyclone on the outside of the combustion chamber is a radial cyclone with cyclone direction opposite to that of a second-stage cyclone. Primary combustion fuel enters a cyclone blade channel from small holes of a front wall surface of a third-stage cyclones by way of multipoint direct injection and is accelerated to be crushed and atomized in a cyclone channel to be mixed with the air, and forms premixed or partly premixed fuel-air mixture at an exit of the tertiary swirling influx to enter a primary combustion zone to be combusted. The low-pollution combustion chamber is applicable to aircraft engine combustion chambers or industry fuel turbine combustion chambers.

Low-pollution combustion chamber adopting fuel-grading and three-stage cyclone air inlet

The invention discloses a fuel and air mixing device for a low-pollution burning chamber of a gas turbine Fuel comprises a main burning level and a duty burning level; and air is supplied by a three-stage cyclone The fuel and air mixing device is characterized in that the central duty level adopts diffusive burning, and the peripheral main burning level adopts premixing or semi-premixing burning The central duty level consists of a centrifugal atomizing nozzle and first-stage cyclone air; and the rotating directions of the first-stage cyclone air and second-stage cyclone air are opposite The fuel of the main burning level is supplied by a multipoint direct-injection type nozzle, the air is respectively supplied by the second-stage cyclone air and third-stage cyclone air, and the rotating directions of the second-stage cyclone air and third-stage cyclone air are opposite The central duty level is used when in low working conditions such as starting and slowing and the like, so that the stable burning range can be widened, the burning efficiency can be improved and the emission of CO and UHC is reduced; and when in large working conditions, the duty level and the main burning level work simultaneously, the duty level provides a stable ignition source for the main burning level, a main burning area is in a lean-oil state, and the temperature is far lower than the temperatureof insulated flame, so that the emission of NOx under the large working conditions can be obviously reduced The fuel and air mixing device can be used for an aerial gas turbine engine or an industrial gas turbine

Fuqiang Liu

Papers

Experimental investigations of spray generated by a pressure swirl atomizer

Investigations of the effects of spray characteristics on the flame pattern and combustion stability of a swirl-cup combustor

Experimental Investigation of Spray and Combustion Performances of a Fuel-Staged Low Emission Combustor: Part I — Effects of Main Swirl Angle

Low-pollution combustion chamber adopting fuel-grading and three-stage cyclone air inlet

Fuel and air mixing device for low-pollution burning chamber of gas turbine