A fluid is a fluid substance, and it is an object that is continuously deformed by any tiny shear force. Fluid is an umbrella term for liquids and gases. It has easy flowability, compressibility, and viscosity. The fluid composed of a large number of molecules that are constantly thermally moving and have no fixed equilibrium position has a certain degree of compressibility, the liquid compressibility is very small, and the compressibility of gas is large, and when the shape of the fluid changes, there is also a certain movement resistance (i.e., viscosity) between the layers of the fluid. When the viscosity and compressibility of a fluid are small, it can be approximated as an ideal fluid, which is an ideal model introduced to study the motion and state of a fluid.
There are two states of motion in fluid flow: laminar and turbulent.
1. Laminar flow, as a layered flow. When the fluid flows at low velocity in the tube, it appears as laminar flow, and its particles move in a smooth straight line along the direction parallel to the tube axis. The velocity of the fluid is greatest at the center of the tube and smallest near its walls. The ratio of the average flow velocity to the maximum flow velocity of the fluid in the tube is equal to 05。
2. Turbulent flow, if the flow rate is very slow, the fluid will flow in layers and not mix with each other, which is laminar flow. If the flow velocity increases, it becomes faster and faster, and the fluid begins to oscillate in a fluctuating manner, which is called transition flow. When the flow velocity continues to increase and the flow line cannot be clearly distinguished, many whirlpools will appear, which is called turbulence, turbulence or turbulence.
The study of fluid flow type is an important part of a basic discipline, in the classification of advection and turbulence two fluid flow modes produce different effects, in this regard also to apply the knowledge of "fluid mechanics", for example, advection is a more common flow mode of fluid in flow, it produces efficiency (i.e., the work done) is relatively stable and continuous, and turbulence is a rotating flow of fluid, because the center of rotation of the fluid is easy to form a "vacuum" Vortex separates some impurities, so the significance of studying the type of fluid flow in general industry is that it can solve the problem of calculating energy consumption in fluid flow, so as to design the selection of piping systems and pumps, fans, etc. In the field of aviation industry, it is of great practical significance to the design of aircraft shape, the development of engines, and the conduct of wind tunnel experiments.
Device function1. Learn the measurement method of straight pipe friction resistance PF and straight pipe friction coefficient. 2. Master the relationship between the friction coefficient and the Reynolds number under different flow rates and its change law. Verify the relationship curves with RE in laminar flow, transition flow, and turbulent flow zones. 3. Determine the local resistance coefficient of fluid flowing through the valve in turbulent flow. 4. The four-point manometry method is used to accurately determine the local resistance. 5. Full touch integrated control, high and stable data transmission, hardware encryption. 6. The device can realize the mobile terminal to scan the code and obtain the introduction of the device process. 