Fluid flow behavior over the throttle body

Aim

Fluid flow behavior over the throttle body.

Introduction

The throttle is the mechanism by which fluid flow is managed by constriction or obstruction. It is located between the air intake filter and intake manifold. It regulates how much air can go into the engine, based on the input through the speed pedal. In this simulation working fluid is Air. The throttle plate and the throttle shaft provide restriction to the flow of intake air. Lesser is the restriction across the flow, lower is the loss of energy. This increases the velocity at the outlet of the throttle body. Throat region has the minimum area available for the air to flow. In order to reduce energy loss, the flow should be accelerated at the throat. Hence, the pressure drop at the throat should be minimum. The region of re-circulating flow formed downstream of the throttle shaft, is known as the wake region. The recirculation of air is caused by the viscous air flow around the throttle plate surface. The medium is displaced when it leaves the surface of the throttle shaft, resulting in turbulent eddies being formed. The presence of eddies make the flow through the wake region turbulent and hence, it should be minimum. There is a region of adverse pressure gradient formed due to excessive loss of momentum near the flow contacting surface. Due to the adverse pressure gradient, the flow near the surface of a body is decelerated. Thus, this pressure gradient precludes the flow from progressing downstream past a certain point, called the point of separation. At this point, the flow becomes separated from the contacting surface of the throttle plate. The position of the point of separation is also an important factor to be considered while analyzing the pressure contours. Stagnation point is a region formed in the air flow field where the local velocity of air approaches zero. In the throttle flow, stagnation point is formed at the tip of the leading edge of the throttle plate where the air is brought to rest due to sudden obstruction in flow. In this region, the static pressure increases as the velocity drops. 

The mesh size is 2mm

In this simulation fixed embedding use near the throttle.

• Scale 2
• no of layer 5

Inlet Pressure 1.5e5 Pa

Outlet Pressure 1e5 Pa

Geometry

Mesh

Pressure Contours

Velocity Contours

Total Cell Plot

Mass Flow Rate Plot

Pressure Plot

Velocity Plot

Pressure Animation

Velocity Animation

Conclusion

• Maximum pressure observes at the left side of the throttle valve.
• Maximum Velocity observes at the upper and bottom side of the throttle.
• Recirculation in flow observes at the right side of the throttle.
• Hign and low-pressure zone created at the near of throttle.