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what is fluids?

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what is fluids?

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Definition of Fluids in Physics

In physics, a fluid is defined as a substance that deforms continuously when subjected to a tangential or shear stress, no matter how small the stress may be. This means that fluids will flow or change shape under applied forces, unlike solids which resist deformation. Fluids include both liquids and gases, as they can take the shape of their container and exhibit flow characteristics. 1 Understanding Fluid Mechanics and Stress

Fluids are distinguished from solids by their ability to flow and their lack of fixed shape. Their properties are often analyzed using the continuum assumption, which treats fluids as being continuously distributed throughout a region, allowing properties like density, pressure, and velocity to be defined at every point. Common examples of fluids include water, air, oil, and mercury. 2 Basics of Fluid Mechanics | Ansys Innovation Courses

Fluids are further classified as Newtonian or non-Newtonian based on how their shear stress relates to shear rate. Newtonian fluids, like water and air, have a linear relationship between shear stress and shear rate, while non-Newtonian fluids do not follow this linear relationship. 1 Understanding Fluid Mechanics and Stress

Would you like to know more about how fluids are classified or how their properties are analyzed in simulations?

[directcustomer]

what is fluids?

[AnsysGPT]

Question to Ansys Assistant

what is fluids?

Response from Ansys Assistant

Definition of Fluids in Physics

In physics, a fluid is any substance that deforms continuously under the application of a shear stress, regardless of how small the stress may be. This includes both liquids and gases, which take the shape of their container and flow when subjected to forces. The fundamental property distinguishing fluids from solids is their ability to flow and change shape rather than maintaining a fixed form. 1 Introduction to Fluid Mechanics

Classification: Newtonian and Non-Newtonian Fluids

Fluids are classified based on how their shear stress relates to the rate of deformation (shear rate). Newtonian fluids, such as water, air, oil, and mercury, exhibit a linear relationship between shear stress and shear rate, described by Newton's law of viscosity: τ = μ(du/dy), where τ is shear stress, μ is dynamic viscosity, and du/dy is the velocity gradient. For Newtonian fluids, viscosity remains constant regardless of the shear rate. 2 Recap and Conclusion

Non-Newtonian fluids do not follow this linear relationship. Their viscosity can change depending on the shear rate or other factors. Examples include shear-thinning fluids (viscosity decreases with increased shear rate, like polymer solutions), shear-thickening fluids (viscosity increases with increased shear rate, like some suspensions), and Bingham plastics (require a yield stress before they flow). The classification is often based on mathematical models describing their behavior, such as the power law or Herschel-Bulkley models. 2 Recap and Conclusion

Would you like to learn more about how Newtonian and non-Newtonian fluids are modeled in Ansys simulation tools?

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