Ancestors of Thermodynamics

P M V SubbaraoProfessor

Mechanical Engineering Department

I I T Delhi

Beak through Inventions for Formulation of Thermodynamics …..

The Family of Steam Engines

A Hardware Responsible for the Greatest Engineering Science

Original Design of Savery Engine

Thermodynamic Analysis of Savery Engine - 1

Thermodynamic Analysis of Savery Engine - 2

Thermodynamic Analysis of Savery Engine - 3

The Family of Steam Engines

James Watts Engine

Model for Working of Muscle

Performance of Muscle Generating Cyclic Force

Cyclic Performance of Leg Muscle

Working of An Isolated Muscle

Cyclic Operation of Heart

Description of Heart Cycle

• A is the end-diastolic point; this is the point where contraction begins.

• Pressure starts to increase, becomes rapidly higher than the atrial pressure, and the mitral valve closes.

• Since pressure is also lower than the aortic pressure, the aortic valve is closed as well.

• Segment AB is the contraction phase.

• Since both the mitral and aortic valves are closed, volume is constant.

• For this reason, this phase is called isovolumic contraction.

• At point B, pressure becomes higher than the aortic pressure and the aortic valve opens, initiating ejection.

• BC is the ejection phase, volume decreases.

• At the end of this phase, pressure lowers again and falls below aortic pressure.

• The aortic valve closes.

• Point C is the end-systolic point.

• Segment CD is the isovolumic relaxation.

• During this phase, pressure continues to fall.

• The mitral valve and aortic valve are both closed again so volume is constant.

• At point D pressure falls below the atrial pressure and the mitral valve opens, initiating ventricular filling.

• DA is the diastolic filling period.

• Blood flows from the left atrium to the left ventricle.

• Atrial contraction completes ventricular filling.

Cyclic Operation of deceased Heart