Fabrication and Experimental Evaluation of a Vascular-Cooled Polymer Matrix Composite Single-Cylinder Engine Block

Abstract

Over the proceeding decades, polymer-based materials have become increasingly crucial to modern automobile design due to their high strength-to-weight and stiffness-to-weight ratios, ability to be manufactured into complex geometries, corrosion resistance, and high structural damping. However, metals remain the dominant material in internal combustion engines (ICEs) mainly due to the hot temperatures experienced. Polymers are susceptible to softening and even degrading in these hot under-the-hood environments. Here, we apply vascular cooling to an engine block to address this issue. In vascular cooling, a fluid is circulated through a network of small channels manufactured directly into the structural material to regulate its temperature, improving the structural performance for ICE applications. In addition to the standard water jacket already present for engine cooling, vascular cooling of the polymer matrix composite (PMC) is intended to reduce the temperature from approximately 120 degrees C-250 degrees C commonly present in the engine to under 100 degrees C. At these temperatures, the PMC is able to take full advantage of its superior properties to provide substantial improvements to the engine, including reduced mass and radiated noise. In this study, we designed and fabricated a single-cylinder PMC intensive engine block utilizing vascular cooling. The engine block was then tested for over 100 h of durability testing as a component of an operating engine. Results demonstrate normal function of the engine with the PMC block throughout testing, significant reduction in temperature using vascular cooling, and significant reduction in radiated noise.