A Simulation of Lean Hunting in Gasoline Engines

911809

09/01/1991

Event
International Off-Highway & Powerplant Congress & Exposition
Authors Abstract
Content
Carburetor engines with an inertia governor sometimes exhibit a self-excited oscillation in rotational speed, called hunting. The mechanism of hunting has been extensively studied for many years. It is our general understanding that the dynamic characteristic of the inertia governor is the primary factor to explain the phenomenon. However, the existence of another kind of hunting, called lean hunting, where lag in air-fuel ratio plays a more important role than the dynamic characteristic of the inertia governor, was reported by Tanaka(1,2). His previous papers, showing various experimental measurements of oscillating engine speed, air-fuel ratio and peak cylinder pressure, explain the nature of the phenomenon. To provide the foregoing work with a theoretical ground, we developed a mathematical formulation for the mechanism of lean hunting. Our new paper demonstrates, by numerical calculations, the process in which engine speed becomes oscillatory reaching a limit cycle, as air-fuel ratio becomes leaner.
Meta TagsDetails
DOI
https://doi.org/10.4271/911809
Pages
10
Citation
Watanabe, Y., and Tanaka, M., "A Simulation of Lean Hunting in Gasoline Engines," SAE Technical Paper 911809, 1991, https://doi.org/10.4271/911809.
Additional Details
Publisher
Published
Sep 1, 1991
Product Code
911809
Content Type
Technical Paper
Language
English