This chapter details the unique challenge of managing electric drivetrain (EDT) waste heat in electrified aircraft propulsion (EAP) architectures. Hybrid-fueled and hybrid-electric propulsion systems make up the hybrid propulsion family, and these are composed of various combinations of fueled-engine and battery-electric propulsion systems. All comprise EAP systems, and they are analyzed here to assess their thermal performance and thermal management (TM) impacts on the aircraft. An introduction to the TM of HEPS is followed by a discussion of EDT heat sources and aircraft heat sinks. Next follows a summary of TM challenges specific to EDTs and thermal management system (TMS) heat acquisition and component cooling approaches. A review of TMS architectures leads to a reference TMS that is used to introduce general analysis concepts and heat transport and rejection components, including the underlying physics-based equations necessary for their analysis. The chapter concludes with a detailed step-by-step design of the reference TMS, listing constraints, imposed conditions, calculated values, and free parameters.

This chapter describes examples of basin modeling in 1D and 2D and shows the power of basin models to predict pore pressure. The fundamental conservation laws and partial differential equations used in basin modeling are presented. Mathematical derivations for 1D shale-on-shale and sand-on-shale compaction and pore pressure models are given in detail. While seismic models for pore pressure prediction predict pore pressure given present-day geology, basin modeling provides an alternate technique that describes the pore pressure distribution using transient models that depend on fluid and heat flow during geologic times along with other phenomena, such as changes in facies and geologic structures in paleotimes. So this approach not only tells us what the pore pressure is today but allows us to investigate the effect of uncertainties in geology in the past and their imprint on the present-day pressure distribution.