STUDY ON DETERMINING THE APPROPRIATE AIR INJECTION ANGLE IN THE AIR SUPPLEMENT SYSTEM ON THE EXHAUST MANIFOLD OF MOTORCYCLE ENGINES USING CARBURETOR

Abstract

The rich combination is the basic feature of gasoline engines equipped the carburetor fuel
system. Therefore, adding air to the exhaust can be an effective method to utilize heat in the
exhaust to enhance the oxidation reaction on the exhaust manifold. Moreover the addition air will
overcome the limited use the three way catalyst in this engines because it improves the oxidation
environment in the catalyst thereby enhancing the conversion efficiency of CO and HC. However, in
order to improve the efficiency of the catalyst, besides the amount of additional air and the
mixture temperature, the degree of homogeneity between the exhaust gas and additional air is
also an important parameter. In this paper, we will present the process of evaluating the influence
of the air injection angle on the exhaust manifold () on the mixing efficiency between the
exhaust gas and the supplementary air. Research results show that, with  = 120o, the effective
mixing zone of two gas streams reaches the highest value, up to 33.4%.