Extensive Property

Definition

An extensive property is a physical quantity whose value depends on the size or extent of the system being measured. Examples include mass, volume, and total energy, which change when the size of the system changes. This concept is crucial for understanding how various properties of fluids behave when considering different control volumes, especially in relation to conservation laws.

5 Must Know Facts For Your Next Test

1. Extensive properties are additive; for example, if you combine two separate systems, the total extensive property will be the sum of the individual properties.
2. In thermodynamics, understanding extensive properties is essential for formulating equations that describe energy conservation within a system.
3. When dealing with processes in fluid mechanics, extensive properties help in analyzing changes in mass and energy as fluid flows through different control volumes.
4. An extensive property can be converted into an intensive property by normalizing it with respect to the system size, like density which is mass per unit volume.
5. In Reynolds Transport Theorem, extensive properties play a key role as it relates the change of extensive properties within a control volume to the flow of those properties across its boundaries.

Review Questions

• How do extensive properties differ from intensive properties, and why is this distinction important in fluid mechanics?
  • Extensive properties differ from intensive properties in that their values depend on the amount of substance or size of the system. For instance, mass and volume are extensive, while temperature and pressure are intensive. This distinction is crucial in fluid mechanics because understanding how these properties behave allows engineers to apply conservation laws accurately and design systems that effectively manage fluid flow and energy transfer.
• Discuss how extensive properties influence the application of Reynolds Transport Theorem in analyzing fluid flow.
  • Extensive properties are fundamental to Reynolds Transport Theorem as they help relate the changes within a control volume to the flow across its boundaries. The theorem allows for the mathematical treatment of the transport of these extensive properties over time, providing a framework to analyze mass and energy balances. This framework is essential for predicting how fluids behave under various conditions and for designing systems that utilize these principles.
• Evaluate how understanding extensive properties aids in solving practical problems related to energy conservation in fluid systems.
  • Understanding extensive properties is vital for solving practical problems involving energy conservation in fluid systems because it allows for precise calculations of energy changes as fluids interact with their environments. By using extensive properties like total energy and mass, engineers can apply principles such as conservation of mass and energy effectively. This knowledge enables them to design efficient systems that minimize energy loss and optimize performance, which is crucial in applications like power generation, HVAC systems, and fluid transport.

Related terms

Intensive Property:

An intensive property is a physical quantity that does not depend on the size of the system, such as temperature or pressure.

Control Volume: A control volume is a specified region in space through which fluid can flow, often used in analysis to apply conservation principles.

Thermodynamic System: A thermodynamic system is a defined quantity of matter or region in space chosen for analysis, which can be open, closed, or isolated.