抄録
Most of the previous research work on engine speed hunting has been devoted to discriminating the divergence of a small disturbance given at an equilibrium state, resulting in a hunting frequency estimation different from that of the actual system. In addition, it is impossible to predict whether limit cycle would occur or not. In the author's previous report, a numerical simulation was given, which showed a transient process of a small oscillation developing into a sustained oscillation with a large amplitude. For a better understanding, however, it is desirable to be able to get the amplitude and frequency of hunting analytically. In the present report is given a linear approximation considering a phase lag of the subventuri pressure responding to the engine speed fluctuation. The results show that this linear theory surely predicts the instability of an equilibrium state at higher idling speeds, but riot the stability at lower speeds, and gives the hunting frequency almost correctly ; but the calculated value of the logarithmic increment of amplitude at the largest hunting state is twice that of the nonlinear simulation.
