Probably the most remarkable of all engineered systems that depend upon the utilization of fluid mechanics are the transportation vehicles, airplanes and ships. These vehicles are designed to sustain themselves in the fluid medium through which they move, consuming the least power possible for the speed they attain and without experiencing damage or destruction even under adverse weather conditions. Their structures are shaped to provide a fluid force to suspend the vehicles in a stable manner against the pull of gravity and disturbances in the medium through which they travel. The automobile is the prime example of a complex mechanical, fluid mechanical and electrical system that integrates the various functions of its components into a remarkably sophisticated consumer product. Air and liquid fuel flowing into the cylinders are precisely metered to control the power of the engine, ensure the efficiency of combustion and to reduce to a minimum the creation of air pollutants in the exhaust.
Hydraulic systems transmit power to operate the brakes and, in some cases, the steering system.
Fans circulate fresh air throughout the interior, the air flow having been cooled by an air conditioner or heated by hot fluid from the engine cooling system. A lubricating oil pump circulates oil for both lubrication and cooling of hot engine parts. A fuel pump extracts fuel from the fuel tank and delivers it under pressure to the carburetor or the fuel injection system. A fan draws cooling air past the radiator, thereby cooling the engine coolant fluid. Even the windshield cleaning fluid is pumped upon demand, spraying the windshield when needed.