旋流器关键参数对双旋流冷态流场特性的影响

Effects of Key Parameters of Swirler on Non-Reaction Flow Field Characteristics Generated by Double-Swirler

关键词:  燃烧室  中心分级  双旋流器  中心回流区  PIV方法

Key words:  Combustor  Concentric staged  Double-swirler  Central recirculation zone  PIV method

摘要:

为了探究中心分级双旋流燃烧室内冷态流场特性，采用粒子成像测速法PIV（Particle image velocimetry）方法进行研究，揭示了值班级与主燃级旋流的相互作用及其对双旋流燃烧室内流场的影响机制，获得了值班级旋流强度、主燃级旋流强度和两级旋流之间的空气比例等旋流器关键参数对燃烧室内流场的影响规律。结果表明：在基准方案下，仅值班级工作时不能形成中心回流区，随着旋流较强的主燃级加入，在主燃级和值班级旋流的相互作用下能够形成稳定的中心回流区；在中心分级双旋流燃烧室中，随着值班级旋流强度的增大，中心回流区的扩张角、径向宽度和回流量明显增大。当值班级旋流的旋流数大于0.6时，中心回流区尺寸随旋流强度的增大无明显变化；当主燃级为强旋流时，主燃级旋流强度对中心回流区影响较小，旋流强度的增大对中心回流区的发展有轻微的抑制作用，但在主燃级旋流数分别为0.723，1.017和1.553时均能形成稳定的中心回流区；对于值班级旋流较弱、主燃级旋流较强的中心分级双旋流燃烧室，主燃级和值班级之间空气比例的增大能够明显导致中心回流区扩张角、径向宽度和回流量增大。

Abstract:

The non-reaction flow characteristic of a concentric staged double swirl combustor was investigated by particle image velocimetry （PIV） method. The interaction process between main stage and pilot stage swirling flow and the influence mechanism on the flow field in this double swirl combustor were revealed. The effect rules of key parameters such as the pilot stage swirling intensity， the main stage swirling intensity and the air proportion between main stage and pilot stage on the flow field characteristics were obtained. According to the results， the central recirculation zone （CTRZ） cannot be formed in the single pilot stage combustor with reference parameters. With the addition of the main stage strong swirling flow， a CTRZ appears under the interaction of the main stage and the pilot stage swirling flow. In the concentric staged double swirl combustor， the divergence angle and width of the CTRZ， as well as the recirculated mass flow rate increase significantly as the increase of the pilot stage swirling intensity. When the swirl number of the pilot stage swirling flow is greater than 0.6， the size of CTRZ does not change obviously with the increase of swirling intensity. When the main stage is strong swirling flow， the CTRZ changes little with the increase of the main stage swirling intensity. Increasing the swirling intensity will slightly inhibit the development of the CTRZ， but a stable CTRZ can be formed when the swirl number of the main stage swirling flow is 0.723， 1.017 and 1.553，respectively. For the concentric staged double swirl combustor with a weak swirling pilot stage and a strong swirling main stage， the divergence angle and width of the CTRZ， and the recirculated mass flow rate increase noticeably as the increase of the air proportion between main stage and pilot stage.