Optimization Design of the Intake System Based on an Engine for FSC

Abstract

The full name of FSC is Formula Student China. Students are required to design, process and assemble a racing car within one year. According to the competition rules, the engine displacement used should not be more than 710 ml, and a limiter with a diameter of no more than 20 mm should be set at the intake pipe, which makes the original engine characteristics different from the commonly used racing conditions. The design of the intake system will directly affect the dynamic performance of the engine. The main content of this paper is to optimize the intake design of a 675 ml engine used for FSAE racing. By using CATIA modeling and AVL BOOST one-dimensional simulation, the influence of intake manifold and other dimensions on the engine characteristics is analyzed, and we design the intake dimensions for FSC racing car. Through the boost simulation, 3.5L volume is selected as the final volume of the plenum after considering the layout space. On this basis, the shape of the plenum is modeled and 3D simulated, and the scheme with better outlet mass flow rate and the uniformity of each cylinder is selected as the final result. After considering the layout space, through the simulation of intake manifold length in 90–230 mm, it is found that with the increase of manifold length, the peak value of engine torque gradually moves to low engine speed. Because the commonly used engine speed of FSC racing car is about 7000 r/min, 170 mm is selected as the manifold length finally. Through the simulation of manifold diameter, it is found that in the range of 32–42 mm, with the increase of manifold diameter, the peak value of engine torque gradually moves to high engine speed, and finally the manifold diameter is determined as 34 mm.