Propulsion systems are devices that provide thrust force for aircrafts, based on reaction principles. For traditional propulsion systems, such as gas turbines, rocket engines, ramjets, and scramjets, a higher thrust-weight ratio and greater thermal efficiency are desirable characteristics that can be achieved through efficient combustion, optimized flow structures, advanced thermal protection strategies, and the use of high temperature resistant materials. Another option to improve performance and efficiency is to develop high-performance propulsion systems, such as turbine-based combined cycle (TBCC) or rocket-based combined cycle (RBCC) systems, which extend the function of engines by combining different types of traditional engines. Some propulsion systems rely on highly integrated power systems that can operate in different media. Overall, propulsion systems are developing towards the goals of large thrust, high speed, and long endurance, for both civil aircrafts and defense technology.

Heat transfer and flow dynamics are the main concerns for propulsion systems based on reaction principles. Thermal protection has become the biggest problem for aircraft operating at hypersonic speeds, due to external aerodynamic heating and internal combustion heat. In addition to more research on thermal management, research into advanced spray, combustion, and flow control technology is also necessary to ensure high combustion efficiency in advanced propulsion systems. Novel or optimized computational and experimental methods can be applied to measure heat transfer and flow dynamics within propulsion systems. In addition, new concepts and technologies have been developed and applied to improve propulsion system performance, such as powder fluidization, powder combustion, supercritical fluid heat transfer, and nanofluid heat transfer.

This Special Issue is focused on bringing together innovative developments in the fields of heat transfer and fluid dynamics for applications in advanced propulsion systems. We welcome both original research and review articles.

Potential topics include but are not limited to the following:

• Potential topics include, but are not limited to:
• Heat transfer enhancement
• Turbulent combustion simulation
• Supercritical fluid heat transfer
• Laser-based combustion diagnostics
• Spray dynamics
• Nanofluid heat transfer
• Internal and external cooling of turbine blades
• Transpiration cooling for thermal protection
• Multiphase flow
• Aerodynamics of engine components
• Combustion instability
• Power fuel fluidization and combustion technology
• Overall design of engines