嵌套式螺旋药柱燃烧特性影响因素探究

Study on influencing factors of combustion characteristics for the nested helical grain

为进一步探究嵌套式螺旋药柱燃烧特性影响因素,以氧气作为氧化剂,在初始氧化剂通量约为3.0 g/(cm^(2)·s)条件下,对比分析了叶片数量、叶片旋转角和燃料间基础退移速率差异性对嵌套式螺旋药柱燃烧特性影响,主要包括退移速率及特征速度两方面。实验结果表明,适度增加叶片数量、叶片旋转角以及组成燃料间基础退移速率的差异,均有利于提高药柱退移速率和特征速度。但受ABS螺旋基体退移速率和特征速度较低的影响,叶片数量过高将降低药柱整体的燃烧性能。同时,受叶片引导旋流强度的影响,增大叶片旋转角对提高药柱退移速率存在最优值,而增大嵌套式螺旋药柱组成燃料间的基础退移速率差异性,则能够有助于螺旋特征结构的形成,从而提高药柱特征速度。此外,填充纯石蜡燃料的嵌套式螺旋药柱退移速率并未得到提升,其可能原因在于ABS叶片抑制了石蜡液滴夹带。

In order to further explore the influencing factors on combustion characteristics of the nested helical grain,the firing test was carried out.Using oxygen as the oxidizer with initial mass flux about 3.0 g/(cm^(2)·s),the effects of the number of blades,blade rotation angle and the difference of basic regression rate on the combustion performance for the nested helical grain were compared and analyzed,mainly including regression rate and characteristic velocity.The test results show that moderately increasing the number of blades,the rotation angle of the blades,and the difference in the basic regression rate between the component fuels are all beneficial to improving the regression rate and characteristic velocity of the grains.However,due to the low regression rate and characteristic velocity of the ABS helical matrix,excessive increase of blade number will decrease the overall combustion performance of the grain.Meanwhile,affected by the blade-guided swirl strength,rotation angle of the blade has an optimal value for improving regression rate of the grain.Increasing the difference of the basic regression rate between the fuel components of the nested helical grains can help the formation of the characteristic helical structure,further increasing the characteristic velocity.In addition,the regression rate of the nested helical grains filled with pure paraffin fuel is not improved,possibly because ABS blades inhibit the entrainment of paraffin droplets.