CAREER: Control of Soot Growth Dynamics by Strong Tunable Acoustic Fields

在本项目中，测试了一种提高燃烧固体颗粒产物生长速率的新策略。该技术包括用强声场照射肮脏燃烧系统的流出流；这增强了烟灰的聚集，便于后续的收集。此外，当火焰嵌入声场时，会发生有趣的火焰动力学。确定了燃烧过程与声学的耦合关系。试图通过调节声场来控制火焰特性。诊断系统追踪了火焰通过声场产生的烟尘。烟尘形态由采样和散射测量确定，冲击器测量表征了烟尘尺寸分布，声场对局部火焰特性的影响随后是火焰区域的流场、温度和物质测量。计算补充了实验工作。澄清烟灰生长物理的好处是显著的。大多数实际的大型燃烧器使用湍流非预混火焰，这可能会产生大量的烟尘，降低火焰中的烟尘数量浓度对环境的影响是显著的。目前的法规不要求对排放物中的颗粒大小分布进行表征，但最近对健康风险因素的资助改变了这一点。

ABSTRACT CTS-9702327 In this project, a novel strategy for enhancing growth rates of solid particulate products of combustion is tested. The technique involves the irradiation of the effluent stream from a dirty combustion system by an intense acoustic field; this enhances the aggregation of the soot and facilitates its subsequent collection. Also, interesting flame dynamics occur when the flame is embedded in the acoustic field. The coupling of the combustion processes to the acoustics are determined. Control of flame properties by tuning the acoustic field is attempted. Diagnostic's track soot production from the flame through the acoustic field. Soot morphology is determined by sampling and scattering measurements, impactor measurements characterize the soot size distribution, and effects of the acoustic field on local flame properties are followed by flowfield, temperature, and species measurements in the flame zone. Computations complement the experimental work. The benefits of clarifying soot-growth physics are significant. Most practical large-scale burners use turbulent nonpremixed flames which potentially produce large amounts of soot, and the impact of reducing the soot number concentration from the flame is environmentally significant. Current regulations do not require characterization of particulate size distribution in emissions, but recent fundings on health risk factors many change this.