Dynamics of Machines Unit 2,

1. Dynamic Analysis in
Reciprocating Engines
B. VARUN
Assistant Professor(Sr.Gr)
Department of Mechanical Engineering

2. Dynamic Analysis
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Slider Crank Mechanism
Velocity of the Piston
Acceleration of the Piston
Angular Velocity of the Connecting rod
Angular Acceleration of the Connecting rod
End

3. Slider Crank Mechanism
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4. Slider Crank Mechanism
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Consider the motion of a
crank and connecting rod
of a reciprocating steam
engine.
Let OC be the crank and
PC the connecting rod.
Let the crank rotates with
angular velocity of ω
rad/s and the crank turns
through an angle θ from
the inner dead centre
(briefly written as I.D.C).
Let x be the displacement
of a reciprocating body P
from I.D.C. after time t
seconds, during which the
crank has turned through
an angle θ.

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Velocity of the Piston
•𝑽𝒑 = 𝝎 𝒓 𝒔𝒊𝒏𝜽 +
𝒔𝒊𝒏𝟐𝜽
𝟐𝒏

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Acceleration of the Piston
•𝒂𝒑 = 𝝎𝟐
𝒓 𝒄𝒐𝒔𝜽 +
𝒄𝒐𝒔𝟐𝜽
𝒏

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Angular Velocity
•𝝎𝒑𝒄 =
𝝎 𝒄𝒐𝒔𝜽
𝒏𝟐−𝒔𝒊𝒏𝟐𝜽
𝟏
𝟐

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Angular Acceleration:
•𝜶𝒑𝒄 =
𝝎𝟐 𝒔𝒊𝒏𝜽(𝒏𝟐−𝟏)
𝒏𝟐−𝒔𝒊𝒏𝟐𝜽
𝟑
𝟐

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