Dilatant fluids and pseudoplastic fluids belong to which of the following categories?

Explanation:

Dilatant Fluids and Pseudoplastic Fluids

Dilatant fluids and pseudoplastic fluids are types of non-Newtonian fluids. Non-Newtonian fluids do not follow Newton's law of viscosity, meaning their viscosity is not constant and can change under different shear rates. These fluids are categorized based on their behavior under shear stress:

• Dilatant Fluids: These are also known as shear-thickening fluids. Their viscosity increases with increasing shear rate.

• Pseudoplastic Fluids: These are also known as shear-thinning fluids. Their viscosity decreases with increasing shear rate.

Analyzing the Given Options

1. Option 1: Time dependent non-newtonian fluids (Incorrect)

   • Time dependent non-Newtonian fluids, such as thixotropic and rheopectic fluids, change their viscosity with time under constant shear rate. Dilatant and pseudoplastic fluids do not fall into this category.

2. Option 2: Real fluid (Incorrect)

   • A real fluid is a general term for any fluid that exhibits viscosity, unlike an ideal fluid which is considered to have no viscosity. This option is too broad and does not specifically categorize dilatant and pseudoplastic fluids.

3. Option 3: Time independent non-newtonian fluids (Correct)

   • Dilatant and pseudoplastic fluids are classified as time independent non-Newtonian fluids because their viscosity changes with the shear rate but remains constant with time under a given shear rate.

4. Option 4: Newtonian fluid (Incorrect)

   • Newtonian fluids have a constant viscosity regardless of the shear rate. Water and air are examples of Newtonian fluids. Dilatant and pseudoplastic fluids do not exhibit constant viscosity, thus they are not Newtonian.