Simulation tools are transforming the field of aerospace design by enabling affordable, on-demand simulation capabilities. Escape Dynamics, Inc., has been actively using mechanical and computational fluid dynamics (CFD) simulation tools in the design/optimization process of several key components of their space launch system, including antennas for wireless energy transfer, airframe and structural components of a single-state-to-orbit space plane, and a highly efficient combustion-free engine configured to use wireless microwave energy to power a space plane. In this lecture we will summarize the key benefits of using Simulation software tools in aerospace design application, and we’ll focus more narrowly on the CFD and mechanical simulations of our thermal thruster engine. We will specifically focus on comparison between simulation results and the real-world test data and share the lessons we've learned in simulating various heat-exchanger topologies, flow-through nozzles and pipes, and flow-with-heat addition.