Experimental and numerical study on fuel distribution and flame expansion of the enhanced flame holding devices

With the ever growing requirements of modern propulsion and power system, low-resistance and high-efficiency combustion is desperately needed to achieve better performance. In this work, stabilizer integrated with spheno-lugs (SSL) or triangle-lugs (STL) was put forward to enlarge recirculation zone, improve the asymmetry of vortexes to restrain flame oscillation, strengthen fuel diffusion, expand and accelerate flame propagation. Numerical simulation was conducted to analyse its combustion performance. Experiments were performed through visualization methods, such as PIV and high-speed camera; and a new image processing method was used to remove flame radiation for quantitative analysis of flame. SSL mainly aimed at expanding flame propagation in circumferential direction; its flame expansion ratio was promoted from 5.2% to 29.4% at various inlet conditions, and two heights (4.5 mm and 6 mm) of spheno-lugs were compared to obtain their maximum difference of expansion ratio that reached 4.09%. STL mainly worked for accelerating flame propagation in radial direction, which was conductive to higher and more homogenous outlet temperature; for example, all the samples of temperature measured in the middle cross-section of injectors were greater and the maximum improvement was up to 8.26%. The two enhanced stabilizers realized better aerodynamic and thermodynamic performances due to their unique designs.