The paper sheds light on the idle lean blow off(LBO)problem for high fuel air ratio(FAR)com⁃bustor,which is impossible to be addressed with traditional aero combustor design.A significant improvement in aero combustor...The paper sheds light on the idle lean blow off(LBO)problem for high fuel air ratio(FAR)com⁃bustor,which is impossible to be addressed with traditional aero combustor design.A significant improvement in aero combustor design is required to resolve the idle LBO issue.The authors detailed a practical and efficient solu⁃tion,which not only solved the idle LBO issue but also defined the aero-thermal design for high-FAR combustor.The design will usher in a new era of aero combustor.展开更多
The lean blowout experiments of the combustion stability device A (multi-vortexes-dome model combustor) have been carried out at atmospheric pressure. Compared with the device B (single-vortex-dome model combustor), t...The lean blowout experiments of the combustion stability device A (multi-vortexes-dome model combustor) have been carried out at atmospheric pressure. Compared with the device B (single-vortex-dome model combustor), the experimental results show that the device A has a superior lean blowout performance when the combustor reference velocity is within the range from 3.50m/s to 5.59m/s ( while the liner reference velocity is between 3.84 and 6.13m/s), and this superiority will remain stable after the inlet air flow rate reaches a certain value. In order to analyze the phenomena and experimental results, the numerical simulation method is used, and the strain rate and the cold reflux impact are employed to further explain the reason that causes the difference between the two devices' lean blowout characteristics.展开更多
The staged injector has exhibited great potential to achieve low emissions and is becoming the preferable choice of many civil airplanes. Moreover, it is promising to employ this injector design in military engine, wh...The staged injector has exhibited great potential to achieve low emissions and is becoming the preferable choice of many civil airplanes. Moreover, it is promising to employ this injector design in military engine, which requires most of the combustion air enters the combustor through injector to reduce smoke emission. However, lean staged injector is prone to combustion instability and extinction in low load operation, so techniques for broadening its stable operation ranges are crucial for its application in real engine.In this work, the LBO performance of a staged injector is assessed and analyzed on a single sector test section.The experiment was done in atmospheric environment with optical access. Kerosene-PLIF technique was used to visualize the spray distribution and common camera was used to record the flame patterns. Emphasis is put on the influence of pilot burner on LBO performance. The fuel to air ratios at LBO of six injectors with different pilot swirler vane angle were evaluated and the obtained LBO data was converted into data at idle condition. Results show that the increase of pilot swirler vane angle could promote the air assisted atomization, which in turn improves the LBO performance slightly. Flame patterns typical in the process of LBO are analyzed and attempts are made to find out the main factors which govern the extinction process with the assistance of spray distribution and numerical flow field results. It can be learned that the flame patterns are mainly influenced by structure of the flow field just behind the pilot burner when the fuel mass flow rate is high; with the reduction of fuel, atomization quality become more and more important and is the main contributing factor of LBO. In the end of the paper,conclusions are drawn and suggestions are made for the optimization of the present staged injector.展开更多
文摘The paper sheds light on the idle lean blow off(LBO)problem for high fuel air ratio(FAR)com⁃bustor,which is impossible to be addressed with traditional aero combustor design.A significant improvement in aero combustor design is required to resolve the idle LBO issue.The authors detailed a practical and efficient solu⁃tion,which not only solved the idle LBO issue but also defined the aero-thermal design for high-FAR combustor.The design will usher in a new era of aero combustor.
基金supported by the National Natural Science Foundation of China (No. 50876104)the Major State Basic Research Development Scheme of China (No. 2012CB720406)
文摘The lean blowout experiments of the combustion stability device A (multi-vortexes-dome model combustor) have been carried out at atmospheric pressure. Compared with the device B (single-vortex-dome model combustor), the experimental results show that the device A has a superior lean blowout performance when the combustor reference velocity is within the range from 3.50m/s to 5.59m/s ( while the liner reference velocity is between 3.84 and 6.13m/s), and this superiority will remain stable after the inlet air flow rate reaches a certain value. In order to analyze the phenomena and experimental results, the numerical simulation method is used, and the strain rate and the cold reflux impact are employed to further explain the reason that causes the difference between the two devices' lean blowout characteristics.
基金supported by National Natural Science Foundation of China with project No.51306182
文摘The staged injector has exhibited great potential to achieve low emissions and is becoming the preferable choice of many civil airplanes. Moreover, it is promising to employ this injector design in military engine, which requires most of the combustion air enters the combustor through injector to reduce smoke emission. However, lean staged injector is prone to combustion instability and extinction in low load operation, so techniques for broadening its stable operation ranges are crucial for its application in real engine.In this work, the LBO performance of a staged injector is assessed and analyzed on a single sector test section.The experiment was done in atmospheric environment with optical access. Kerosene-PLIF technique was used to visualize the spray distribution and common camera was used to record the flame patterns. Emphasis is put on the influence of pilot burner on LBO performance. The fuel to air ratios at LBO of six injectors with different pilot swirler vane angle were evaluated and the obtained LBO data was converted into data at idle condition. Results show that the increase of pilot swirler vane angle could promote the air assisted atomization, which in turn improves the LBO performance slightly. Flame patterns typical in the process of LBO are analyzed and attempts are made to find out the main factors which govern the extinction process with the assistance of spray distribution and numerical flow field results. It can be learned that the flame patterns are mainly influenced by structure of the flow field just behind the pilot burner when the fuel mass flow rate is high; with the reduction of fuel, atomization quality become more and more important and is the main contributing factor of LBO. In the end of the paper,conclusions are drawn and suggestions are made for the optimization of the present staged injector.
