Analysis of flow resistance and combustion characteristics in the combined application of step and strut

Abstract

A combined application of step and strut was put forward to achieve low-resistance and stable combustion. Strut parameters such as strut widths (15 mm, 30 mm, 45 mm, and 60 mm) and slant angles (20 deg, 30 deg, and 40 deg) affected pilot-ignition performance of step and flame propagation. It was found that flow resistance was increasing with the growing strut width, and 0.15%–2.6% decreasing with the growing slant angle. Here emphasized most, slant angle affected total pressure loss more obviously with the increase of strut width. Also, ignition performance was improved firstly and then impaired with the increase of strut width, the enlargement of strut width could enhance ignition within a certain range. Similarly, at the same strut width (30 mm), ignition limits had the relationship of first decreasing and then increasing with the growing slant angle, which was related to ignition development. Completed flame propagation and stability were achieved to fulfil the entire space in various ways except for 15 mm-width strut. And pilot-ignition zone which worked as ever-burning source enhanced ignition and stability performance, such as 30 deg-strut. The change of flow resistance, ignition performance and flame development with strut width and slant angle was as evaluation indexes for optimizing flame holding device.