Design analysis of the “Schwartz D” based heat exchanger: A numerical study

•A computational mass and heat transfer analysis in SchwartzD (TPMS) based heat exchanger to quantify the thermal performance of the heat exchanger and fluid flow inside TPMS.•Negligible pressure drop penalty in TPMS for the amount of heat taken away from the heat source compared to an empty channel.•TPMS wall thickness has a significant impact on the thermal performance of the heat exchanger.•Continuous decay of reverse flow inside and outside the heat exchanger with either decreasing wall thickness or reducing flow velocity.•The heat exchanger’s thermal performance can change as much as 250% by changing the cells’ wall thickness.•The intricate flow pattern inside TPMS created a quadratic relation between the effective area and Reynolds.•The impact of wall thickness is negligible for very low Reynolds (Re