Thermal–hydraulic analysis of PCHEs using supercritical methane and multistage Tesla valves with staggered alternatingly oriented flow baffles

This paper presents a numerical investigation of a printed circuit heat exchanger (PCHE) featuring NACA 0020 airfoil-profile flow baffles integrated into a multistage Tesla valve structure. Supercritical methane is employed as the working fluid, and its unique thermophysical properties near the critical point are leveraged to enhance heat transfer and flow regulation. A series of staggered baffle configurations with various orientation angles, ranging from $0°$ to $15°$, are systematically analyzed to evaluate their influence on the flow rectification, pressure drop, and thermal performance. Simulations, based on compressible Navier–Stokes and energy equations, are performed over a Reynolds number range of 5000–8000. The results indicate that an increase in the baffle orientation angle promotes the formation of secondary flow structures—such as eddies and recirculation zones—which enhance convective heat transfer by disrupting the thermal boundary layers and increasing the mixing intensity. Furthermore, the periodic expansions and contractions along the serpentine channels generate localized velocity discontinuities, which contribute to improved thermal uniformity. Compared with the benchmark Tesla design in a prior study, the proposed configuration demonstrates more elongated velocity gradients and a broader high-temperature distribution, underscoring the importance of the baffle geometry in passive flow control. These findings offer valuable insights for optimization of compact heat exchangers and highlight the potential of multistage Tesla valves for thermal management in liquefied natural gas (LNG) temperature reduction systems aboard floating production storage and offloading (FPSO) platforms.