Draft Paper UTS
INTRODUCTION While designing a Formula One car the most important and significant aspects the designer has to deal with, is the field of aerodynamics. The aerodynamic designer has two primary concerns: the creation of down force, to help the car steer onto the track and improve cornering forces; and minimizing the drag force, caused by turbulence which in turn decreases the speed of the car (Mohd Syazrul Shafiq Saad, 2010). These factors enhance the performance of the car.
The front wing of the Formula One car is the single most crucial aerodynamic component. This is because the front wing of the car influences the flow of air over the rest of the body since it is the part, which first comes in contact with the air. It also influences the flow of air into the brake ducts, radiator and diffuser and also to the main engine intake. Down force is generated by the front wing due to the ground effect where more force is generated when aerofoil is moving close to the ground surface. This is one of the many factors that are influenced by the front wing. The wing also incorporates many small cascading winglets which refine the flow and ensures that the flow is laminar and attached to the body of the car in order to attain good aerodynamics result.
The Formula One is a very competitive event in which small improvements in the design of the car may largely affect the car’s performance. Hence the use of robust and concrete technology is necessary to produce the best possible design for higher performance. CFD is one of those technologies. CFD, abbreviation of Computational Fluid Dynamics, is a branch of fluid mechanics that uses numerical methods and algorithms to solve and analyze problems that involve fluid flows. The flow of any fluid comprises of three main principles which are: • Conservation of mass. • Newton’s second law of motion. • Energy conservation.
These fundamental principles can be expressed in terms of mathematical equations, which in their most general form are usually partial differential equations. Computational Fluid Dynamics (CFD) is the science of determining a numerical solution to the governing equations of fluid flow and helps to simulate the flow of fluid over the field of interest.
CFD allows engineers to examine the airflow over an automobile or a particular part such as a wing or hood and see the aerodynamic effect and, helps to solve complex problems without losing their integrity due to ease of the software. The main advantages of using CFD software is that the results are obtained without construction of the required prototype and this is very important because it can reduce the cost in constructing the F1 cars. The validity of results is the most important thing that we need to concern about while using the software simulation. Therefore specific parameters and conditions while analysing the data need to be valid. Among various components that contribute to the varying levels of down force it is the front wing that lends itself to theoretical aerodynamic analysis method and techniques for design using the CFD software.
The role of CFD in engineering predictions has become so strong that today it may be viewed as a new third dimension of fluid dynamics, the other two being pure experimentations and pure theory.
OVERVIEW OF FRONT WING OF FORMULA ONE CAR
Front wing of Formula One car is the single most crucial aerodynamic component. The contributing factor for the above statement is the manner in which it influences the flow of air into brake ducts, radiators, diffusers and also main engine intake. The front wing is actually made into readily modifiable components where flaps and small winglets provide different levels of down force distribution as per the handling requirement of the driver during the race. The dynamic balance of the Formula One car is determined by load on the front wing which is required to be easily modified.
The basic front wing of the Formula One car consists of main plane, a pair of aero-flaps and a pair of end plates. The first element of the wing is rectangular in shape which provides air flow to the second element lower surface so that the latter’s incidence may be increased at a very high angle.
Now a day’s front wing is of two or three element aerofoil which is not actually straight along its span. On the other hand the main flap is a rectangular platform having different shapes due to downstream flow constraints. Aerodynamic down force on the Formula One car is not only generated by the difference in the air pressures on two sides of the main plane but also use to aerodynamic theory of venture. The venture theory shows that by reducing height of the main plate to ground, the velocity of air flowing through is increased and low air pressure is created which results in further down force.
Many researchers have studied the means to enhance the aerodynamic performance and also the effect these changes have on the overall performance of the car employing analytical and experimental methods. Different aerofoil shapes were considered for the design and were analysed during cornering, straight line braking and straight line acceleration conditions. These shapes were tried for single and dual wing configurations. The results showed the importance of maintaining a proper lift to drag ratio and that the front wing down force had to balance the rear wing down force for optimal results.
Comparatively the front wing of an F1 car has a lot of constraints unlike the rear wing and other parts. It is required to have a neutral central section and for a fruitful purpose it must be at least 50 cm in length and cannot induce any amount of down force, hence it is called as neutral central section. There is freedom though in the number of cascades and the flexibility of the wings it is not availing to specify or limit the number of cascades and its flexibility before actual design is done and tests are carried on it. It is found that the stability of a car, while slipstreaming, improves when the wings are flexible. Also the point to be considered is that the closer the wings are to the ground, the more is the down force that it produces, since it makes use of the ground effect of the car. But according to the regulations specifications the minimum ground clearance of the car at standstill position which cannot be compromised on. Hence in order to make utmost use of this regulation flexible wings are added which move down during cornering which induces a higher down force on the car and improves its handling and stability. The combined effect of the above factors proves to be the heart of design of front wing of the Formula One car considering the aerodynamics point of view using CFD.