In this paper the acoustic response of a combustion chamber is studied by assuming different pressure field excitation. The viscous effects on the combustion chamber and the finite impedance of the walls have been modeled with a first order system, which damps the resonance oscillation created by combustion. The characterization of the acoustic response of the combustion chamber has been used to identify the source of the excitation in order to distinguish normal combustion from knock. Two engines, a conventional spark ignited (SI) and a turbulent jet ignition (TJI) engine, were used, fueled with gasoline and compressed natural gas (CNG), respectively. The pressure fluctuations in the combustion chambers are analyzed and a pattern recognition system identifies the most likely source of excitation. This new criteria for knock identification permits a more consistent differentiation between knocking and no-knocking cycles, independent on the amplitude of the phenomenon, thus allowing the improvement for knock control algorithms, specially with combustion modes which heavily excite resonance, such as turbulent jet ignition or homogeneous charge compression ignition (HCCI).

在本文中，通过假设不同的压力场激励来研究燃烧室的声学响应。燃烧室的粘滞效应和壁的有限阻抗已通过一阶系统建模，该系统可抑制由燃烧产生的共振。燃烧室的声学响应的特征已被用来识别激发源，以便区分正常燃烧和爆震。使用了两种发动机，分别是传统的火花点火（SI）发动机和湍流喷射点火（TJI）发动机，分别以汽油和压缩天然气（CNG）为燃料。分析燃烧室中的压力波动，并通过模式识别系统识别最可能的激发源。