Design and Analysis of De-Lavel Restrictor with Throttle Body for Formula Vehicle

The restrictor is a component which controls the mass flow of air passing to the engine. The proposed work focuses on design and analysis of air intake restrictor of Duke 390cc engine which is used in formula vehicles. As an constrain of this system, the air flows through a single circular throat of diameter 20mm. In past decades conventional venture nozzles were used as a restrictor but it leads to nominal press drop. A de lavel nozzle is a tube pinched in the middle, making an asymmetric hourglass shape. It is used to accelerate a higher supersonic speed in the axial direction. The main objective is to utilize De-Laval Nozzle for the minimal pressure drop. The change in pressure will increases the engine power output. The analysis is done by varying design conditions such as three levels of convergent (12,14 and 16 degrees) and three levels of divergent angles (4, 6 and 8 degrees) are taken into consideration. After numerous CFD Simulations, it is inferred that the optimal angles of 14 and 4 degrees for convergent and divergent angles have found the minimum delta pressure. On the other hand, further analysis was carried out on the throttle body valve angle of the optimal restrictor. The throttle body is the part of the air intake system that controls the amount of air that flows into an engine combustion chamber. It consists of a housing unit that contains a throttle plat (butterfly valve) that is rotated by a shaft. In this case, the four different positions such as 5, 45, 75 and 90-degree valve angles are chosen for simulation. From the analysis, the valve angle of 75 degrees is the optimal angle as it provides greater efficiency to the engine. The restrictor with the optimal angle is recommended for use in formula vehicles