Page 98 - Mechanic Diesel - TT

MECHANIC DIESEL - CITS

determined considering the position of throttle valve at fully open condition. Length is chosen based on the air
cleaner side mounting. [14] Air from the air-cleaner enters into the throttle valve and move towards the main
passage. When the throttle plate is almost closed, the air flow into the throttle body cannot though the main
passage, it though the bypass passage. So the throttle plate is opened, the air flows through the main passage
and the amount of airflow through the passage increase when increase the throttle body opening conditions.
Reverse, the amount of the airflow through bypass passage increase.
In this study, we can show the air flow through inside the throttle body that show the flow rate when the throttle
valve opening conditions at the positions are 25, 50 75.100%, With increase in throttle opening conditions the air
flow’s velocity increase through the throttle valve. As the flow travels the throttle body at different conditions the
airflow rate is different. The flow rate through the throttle valve increase with increase in the throttle body opening
positions due to reduce the restriction by throttle body increase the air into the engine.
Intake manifold: An intake manifold is a series of tubes that sit atop the engine. As air enters the car, it travels
through the throttle body, then into the intake manifold and then finally into the engine itself. Basically, the intake
manifold is the last stop on the air’s journey before it reaches the cylinder heads.

There are two basic parts to the intake manifold. There’s the plenum, the large cavity at the top of the manifold,
and the runners, the small tubes that run to each cylinder individually. An intake (also inlet) is an opening, structure
or system through which a fluid is admitted to a space or machine as a consequence of a pressure differential
between the outside and the inside. The pressure difference may be generated on the inside by a mechanism,
or on the outside by ram pressure or hydrostatic pressure. Flow rate through the intake depends on pressure
difference, fluid properties, and intake geometry. Intake refers to an opening, or area, together with its defining
edge profile which has an associated entry loss, that captures pipe flow from a reservoir or storage tank. Intake
refers to the capture area definition and attached ducting to an aircraft gas turbine engine or ramjet engine and,
as such, an intake is followed by a compressor or combustion chamber. It may instead be referred to as a diffuser.
For an automobile engine the components through which the air flows to the engine cylinders, are collectively
known as an intake system [4] and may include the inlet port and valve. An intake for a hydroelectric power plant
is the capture area in a reservoir which feeds a pressure pipe, or penstock, or into an open canal.

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CITS : Automotive - Mechanic Diesel - Lesson 25 - 28 CITS : Automotive - Mechanic Diesel - Lesson 25 - 28