Performance of a Printed Bimetallic (Stainless Steel and Bronze) Engine Head Operating Under Stoichiometric and Lean Spark Ignited (SI) Combustion of Natural Gas
The purpose of this study was to evaluate the durability and operational performance of a bimetallic (stainless steel and bronze) natural gas engine head. The performance was evaluated against a stock cast iron head for comparison. During manufacturing of the printed head, efforts were made to ensure that the internal features, including the fire deck geometry for the two head were identical. The engine was operated under two engine speeds (1200 rpm and 1800 rpm) and two Brake Mean Effective Pressures (6 bar and 10 bar). For each speed and BMEP combination, two equivalence ratios (0.7 and 1.0) were evaluated. In addition to emissions and engine performance data, the research team also took thermal images of both operating heads to ascertain heat transfer and thermal loss differences between the two head materials. The results showed that the brake efficiency, coolant and exhaust temperature were the same for both heads.