High-g field combustion such as in rotary ramjet engines is a promising approach to reduce nitride oxides and combustor size by taking advantage of the flame acceleration due to the buoyancy of the products over the reactants. This paper presents a high-g field combustor design for a rim-rotor rotary ramjet engine. In this device, a premixed flow of air and fuel is ignited in the non-rotating inlet track and then swallowed and stabilized in the rotating combustion chamber. Outboard ignition frees the rotating structure from igniters, increasing the maximal tangential speed of the engine and thus its maximal efficiency. The rotating combustor design benefits from extreme centrifugal fields (10~5 to 10~7 g's) for both stabilizing the flame during ignition and maximize flame velocity. A simple buoyancy-driven combustion model allows estimating the combustor length and shows good agreement with numerical simulations, which demonstrate a combustion efficiency to be higher than 85%, even with some reactants bypassing the flameholder. Experiments demonstrate ignition at tangential speeds from 250 to 380 m/s, combustion efficiency from 60 to 75 % up to a centrifugal acceleration of 7×10~5 g, and positive indicated power.
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机译：高重力场燃烧（例如在旋转冲压发动机中）是一种有前途的方法，可通过利用由于产物相对于反应物的浮力引起的火焰加速来减少氮氧化物和燃烧器的尺寸。本文提出了一种用于轮辋转子旋转冲压发动机的高g场燃烧器设计。在该装置中，空气和燃料的预混合流在非旋转的进气道中被点燃，然后在旋转的燃烧室中被吞咽并稳定下来。外侧点火使旋转结构脱离点火器，从而增加了发动机的最大切向速度，从而提高了其最大效率。旋转燃烧器的设计得益于极端的离心场（10〜5至10〜7 g's），既可以稳定点火期间的火焰，又可以最大程度地提高火焰速度。一个简单的由浮力驱动的燃烧模型可以估算燃烧器的长度，并且与数值模拟显示出良好的一致性，数值模拟表明即使某些反应物绕过了火焰保持器，燃烧效率也可以达到85％以上。实验证明，切向速度为250至380 m / s时点火，燃烧效率为60至75％，直至7×10〜5 g的离心加速度，并具有正指示功率。
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