THE EFFECT OF PIPE STRUCTURE ON THE MIXABILITY OF THE SUPPLEMENTARY AIR ON THE EXHAUST MANIFOLD: A SIMULATION RESEARCH

Abstract

Adding air to the exhaust is a method that has been used on engines equipped
with carburetor fuel systems. This is an effective solution to utilize heat in the exhaust
to enhance the oxidation reaction on the exhaust manifold. Moreover, the addition air
will overcome the limited of equipping the three-way catalyst (TWC) on this engine
because it helps to improve the oxidation environment in catalyst thereby enhancing
the conversion efficiency of CO and HC. In fact, the efficiency of TWC is not only
dependent on the amount of addition air, but also on the other parameters such as:
the position and angle of the nozzle air as well as the mixing texture between the two
streams gas. In this paper we will present the results of simulating the mixing
between two air flows on Ansys fluent. Research results show that, when β = 120o
combined with the addition of a spiral vane continuous, the effective mixing zone of
two gas streams is improved significantly ϕkk by up to 52.1%.