Stall (engine)

Abstract: Using the theory developed in Part I, calculations have been carried out to show the evolution of the mass flow, pressure rise, and rotating-stall cell amplitude during compression system post-stall transients. In particular, it is shown that the unsteady growth or decay of the stall cell can have a significant effect on the instantaneous compressor pumping characteristic and hence on the overall system behavior. A limited parametric study is carried out to illustrate the impact of different system features on transient behavior. It is shown, for example, that the ultimate mode of system response, surge or stable rotating stall, depends not only on the B parameter, but also on the compressor length-to-radius ratio. Small values of this latter quantity tend to favor the occurrence of surge, as do large values of B. Based on the analytical and numerical results, several specific topics are suggested for future research on post-stall transients.

Abstract: A multi-mode internal combustion engine and method of operating the engine is provided which is capable of operating in a variety of modes based on engine operating conditions to enhance fuel efficiency and reduce emissions. The multi-mode engine include a fuel delivery system and control system for permitting the engine to operate in a diesel mode, a homogeneous charge dual fuel transition mode, a spark ignition or liquid spark ignition mode and/or a premixed charge compression ignition mode. The control system and method permits the engine operation to transfer between the various modes in an effective and efficient manner by controlling one or more fuel delivery devices or other engine components so as to move along a continuous transfer path while maintaining engine torque at a substantially constant level.

Abstract: An engine automatic start stop control apparatus controls an engine of a vehicle to be automatically stopped or started in response to driving conditions of a vehicle. Particularly, the apparatus is applied to the vehicle that performs idle stop control for reduction of discharge gas. Herein, the apparatus controls the engine to restart based upon determination for restarting the engine under an engine stop mode. Namely, the apparatus controls the engine to restart if a driver depresses a clutch pedal or if a driver does not depress a brake pedal during an engine stall in which engine speed becomes zero. Thus, it is possible to restart the engine by prescribed operations even if the driver mistakenly recognizes that the engine is stopped by automatic stop control although the engine actually stalls due to an error operation of the driver so that the engine speed becomes zero. This improves drivability for the driver who handles the vehicle, particularly a hybrid vehicle which is capable of independently running by using an electric motor only.