نویسندگان
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Several parameters have significant effect on measure and analyzing of cylinder pressure to obtain accurate
knock data. Acquisition frequency, number of cycles, transducer location and transducer mounting
are measuring parameters. Filtering frequencies, knock windowing, knock model features and threshold
values for knock intensity are important analyzing parameters. Effects of these parameters on knock detection
and methods for optimal selection are investigated by analyzing test bench datasets. Note that optimal
methods aren’t for special operating conditions and almost cover all operating points of engine. Important
parameters for analyzing of transducers’ data, such as digital filtering and Fast Fourier Transformation
(FFT), are introduced. FFT determines the main oscillation frequencies and digital filtering omits undesired
frequencies.
Investigations of test results show that knock is occurred in special frequencies because of acoustic vibration
modes, some methods for determining of these frequencies are introduced. It should be mentioned
that the main oscillation frequency due to knock is about 8 kHz. Exact determination of these frequencies is
important for investigation of filtering and optimal transducer location.
کلیدواژهها [English]
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