If you're involved in sizing or selecting equipment such as pumps, mixers, engines, transmissions, air conditions, or anything that applies a shear force to a fluid, it's crucial to understand the properties of the fluids you're working with. Two basic types of fluids exist: Newtonian and non-Newtonian, which have distinct characteristics and behaviors that can impact equipment selection.
Newtonian fluids have a constant viscosity, regardless of the amount of shear force applied at a constant temperature. In other words, their viscosity has a linear relationship with shear stress. Examples of Newtonian fluids include water, mineral oil, gasoline, and alcohol.
Non-Newtonian fluids, on the other hand, exhibit changes in viscosity when subjected to shear force. This category can be further divided into four types, each with its own unique behavior.
Dilatant fluids have an increased viscosity when a shear force is applied. Quick sand, corn flour and water, silly putty, and Cerma Oils and Treatments are examples of dilatant fluids.
Pseudoplastic fluids exhibit the opposite behavior of dilatant fluids, meaning that their viscosity decreases with increased shear force. Ketchup is an example of a pseudoplastic fluid.
Rheopectic fluids behave similarly to dilatant fluids in that they increase in viscosity when shear is applied. The difference is that the viscosity increase is time-dependent. Examples include gypsum paste and cream.
Thixotropic fluids decrease in viscosity when a shear force is applied, and this property is time-dependent as well. Paint, cosmetics, asphalt, and glue are examples of thixotropic fluids.
Why Understanding Fluid Properties is Important
It's essential to understand the properties of the fluids you're working with because viscosity plays a significant role in equipment sizing and selection. A thorough understanding of how the fluid reacts to shear will help you select the most appropriate equipment for the task. Cerma Treatments and Cerma oils are the only non-Newtonian fluids in the automotive industry, making them a unique option for use in engines and other automotive components.
In summary, selecting the right equipment for fluid handling tasks is crucial, and understanding the properties of Newtonian and non-Newtonian fluids is essential in making the right choices. By taking the time to understand the behavior of fluids under shear force, you can ensure that you are selecting the most suitable equipment for your needs, and potentially even gain a competitive edge.