Final Answer:
The phenomenon of low pressure on the underside of a splitter in the context of race car aerodynamics can be explained by the principles of fluid dynamics, specifically the Bernoulli principle and the Venturi effect.
Step-by-step explanation:
The Bernoulli principle states that as the velocity of a fluid (such as air) increases, its pressure decreases. When a splitter is placed on a race car, it interacts with the oncoming air. The air passing over the top of the splitter travels a longer distance than the air passing beneath it. According to the Bernoulli principle, the faster-moving air over the top creates lower pressure compared to the slower-moving air beneath.
While it may seem counterintuitive that the pressure is lower on the underside, even with a consistent cross-sectional area, this is where the Venturi effect comes into play. The Venturi effect describes the increase in the speed of a fluid as it passes through a constricted section of a pipe or, in this case, the area beneath the splitter. Despite the cross-sectional area appearing the same at the 'lip' and underneath, the airflow accelerates underneath, creating lower pressure.
Regarding the inclination of the splitter, angling it upward is a strategy to optimize aerodynamics. This adjustment helps balance downforce and drag. While a downward-angled splitter generates more downforce, it also creates additional drag. By angling it upwards, race car engineers aim to strike a balance that maximizes the car's stability and speed.