Publication Date




Embargo Period


Degree Name

Master of Science (MS)


Mechanical Engineering (Engineering)

Date of Defense


First Committee Member

Michael R. Swain

Second Committee Member

Matthew N. Swain

Third Committee Member

Singiresu S. Rao


This thesis describes the computational fluid dynamics (CFD) directed analysis used to solve an overheating problem occurring during the warm up period of the crossbred ZKA26 engine in previous research. Internal combustion engine powered generator sets are the primary choice for worldwide operation. Of these generator sets, hardly any use internal combustion automobile engines that are modified beyond the specifications of the manufacturer. These specifications, while well qualified for their intended purpose, are poorly qualified for steady RPM operation as they are used in generator operation. This lack of qualification results in key losses of operational efficiency. This research effort investigates the feasibility of a crossbred engine, previously assembled for the purpose of high efficiency operation for generator use. The engine in question uses a Nissan KA24 block and a Nissan Z20 cylinder head to create a crossbred engine the “ZKA26” with a compression ratio of 14.6:1 and run on a lean mixture of LPG. The chamber surface to volume ratios and heat loss were minimized through the use of hemispherical chambers that lack both squish and swirl areas. The main focus of this study is to investigate and mitigate a failure point in the ZKA26 engine design related to excessive engine block temperatures. Computational Fluid Dynamics was used to find a simulated solution to allow proper engine operation and coolant flow and then experimentally verified with the proposed solutions implemented.


Low heat loss engine