The impingement of a fluid jet on a surface is a canonical problem in fluid mechanics combining the fundamentals of free-jet development, stagnation-point flow and boundary-layer growth. It is also of immense practical importance for its engineering application in heating or cooling a target surface. Through a combination of pioneering numerical and experimental studies, this project will elucidate the thermo-fluid physics of the base system and its extension to incorporate added unsteadiness through jet pulsations and both active and passive surface vibration. While advancing fundamental knowledge, the project will specifically determine the system configuration that would maximise uniform heat removal in a thermal-control technology. This will deliver new scientific knowledge and underpin the development of an energy-efficient thermal-control technology for widespread use in many areas of engineering.