Date of Award


Publication Type

Master Thesis

Degree Name



Mechanical, Automotive, and Materials Engineering

First Advisor

Zheng, Ming

Second Advisor

Ting, David


Aftertreatment spray, Diesel engines, Exhaust pressure wave




Aftertreatment devices are commonly used in diesel engine systems for emission control. To ensure the proper function of the aftertreatment devices, it is often necessary to inject additional fuel or a reducing agent into the exhaust flow. The conditions in the exhaust flow are affected by the exhaust pressure wave, caused by the reciprocating movement of the piston and valves. Therefore, this research investigates the factors that affect the exhaust pressure wave and the consequent impacts of this wave on a liquid spray. First, the exhaust pressure wave action was studied experimentally on a single cylinder diesel engine at various engine operating conditions such as different load, EGR, and exhaust backpressure levels. Then, the gas flow velocity in the exhaust system was estimated with the simulation tool AVL BOOST. A stand-alone shock tube was used to create a condition comparable to the exhaust flow. The impacts of the pressure wave and the gas flow on the aftertreatment spray distribution and the droplet breakup were studied via optical methods.