1, continuity equation

According to the law of conservation of mass. The continuity equation is the concrete expression of the law of conservation of mass (see mass) in fluid mechanics. The premise is that the fluid adopts continuous medium model, and the velocity and density are continuously differentiable functions of space coordinates and time.

2, energy equation (also known as Bernoulli equation)

According to the law of conservation of energy. The energy equation is one of the basic equations for analyzing and calculating the heat transfer process, which is usually expressed as follows: the increment of internal energy of fluid element is equal to the sum of the heat entering the element through heat conduction, the heat generated in the element and the work done by the surrounding fluid on the element.

physical significance

Continuity equation is the concrete expression of the law of conservation of mass in fluid mechanics.

Bernoulli equation is a dynamic equation for the stable flow of ideal fluid, which means that the sum of pressure potential energy, kinetic energy and potential energy at any two points on the streamline remains unchanged when the viscosity loss is ignored.

Application of continuity equation and Bernoulli equation;

1, engineering application

Fluid mechanics is widely used in engineering fields, such as ships, airplanes, automobiles, water conservancy and architecture. Through the research and analysis of fluid motion law, the design can be optimized and the efficiency and performance can be improved.

2. Prevention and control of natural disasters

Fluid mechanics also plays an important role in the prediction and prevention of natural disasters, such as numerical simulation and prediction of natural disasters such as storm surges and floods.

3. Environmental protection

Fluid mechanics is also applied to the control and treatment of environmental pollution. For example, hydrodynamic simulation can help people better understand the law of pollutant diffusion, so as to effectively predict and control pollution.

4. Medical application

The application of fluid mechanics in medical field is increasing day by day, such as blood circulation simulation, diagnosis and treatment of heart disease, etc.

5. Basic scientific research

Fluid dynamics is a part of basic scientific research and also has important applications in physics, astronomy and other fields.