Analysis On Torsional Vibration And Simple Harmonic Torque Characteristic Of 4100 Diesel

It is the important research fields of internal-combustion engine to study crankshaft torsional vibration and torsional vibration excitation harmonic engine torque. By means of analyzing in-depth the two problems that torsional vibration characteristics and the characteristics of harmonic torque, this thesis put up with the stable condition and corresponding solutions. Research on the internal combustion engine working conditions of non-stable characteristics of torsional vibration, the steady working conditions and non-steady speed calculation of harmonic torque to the internal-combustion engine's study both in theoretical and project pragmatic aspects.With the 4100QB diesel engine test-bed in the laboratory as the research base, this thesis analyzes the crank shafting torsion features of internal-combustion engine's stabilization, confirms the torsion modal during the the foremost two orders of shaft, and studies the impacts made upon the shaft torsion features by the stiffness of different shaft-connecting joints. Working conditions for non-steady speed, analysis of the mentioned rate on the characteristics of torsional vibration,resonant frequency of non-steady-state angular shaft vibration amplitude and smaller than the steady state, with the rate increase up, first and second order resonance angular vibration amplitude decreasing trend. non-resonant mode 2.0 and 4.0 the main hannonic torsional vibration properties with little change in the rate mentioned.Internal combustion engine provided by the French Institute of reference PA6 harmonic torque diesel engine gas pressure changes with the average fitting curve indicates, calculate the indicated mean effective pressure conditions corresponding to the harmonic torque. After a moment with the measured harmonic comparative analysis of large diesel engines are currently used in the harmonic coefficient of the gas can not be used for small and medium diesel engines torque calculation of harmonic, the amplitude have the large deviation. Small Diesel Engine torque harmonic amplitude and mean effective pressure was between 3 powers. Speed on the harmonic analysis of the impact of torque in the same general speed of the mean indicated pressure higher harmonic torque corresponding to the larger amplitude, but little change in the phase. Using the known speed of the harmonic torque is calculated by interpolating harmonic under any speed torque is feasible. Working conditions for non-steady speed of harmonic torque, speed up the process in the indicated mean effective pressure increases with time gradually increased overall, the work cycle time increased gradually with time short, the measured harmonic torque of the gas non-stable condition is the basic continuous. Derived through the harmonic moment generating function, moment generating functions are harmonic moments of gas compared with the measured difference between the small, proofs of torque with a simple harmonic function to calculate the gas torque generated is feasible.