Lattice heat sinks offer high thermal performance, but their complex geometry causes large pressure drops under jet cooling. This study investigates the thermal-fluid performance of topology-optimized lattice heat sinks under vertical jet impingement. The lattice-density optimization method is applied to control lattice thickness locally, and three unit patterns―such as CC, BCC, and FCC―are mapped onto the optimized domains. The evaluation focuses on pressure drop, base temperature, and thermal efficiency index. Results show that designs with volume constraints allow more fluid-solid interaction, leading to thinner thermal boundary layers and lower surface temperatures. The optimized unit pattern depends on the design domain: CC is more effective in tall, simple domains due to low flow resistance, while BCC performs better in shallow or complex domains due to its larger surface area. These findings suggest that selecting unit patterns based on local flow characteristics is essential. This study serves as a preliminary step toward multi-pattern lattice design for achieving high-performance, jet-impingement-cooled heat sinks.
KIKUCHI et al. (Wed,) studied this question.