Lesson 5.3 Rheological Flow Properties of AB Materials PDF

Lesson 5.3 Rheological Flow Properties of AB Materials ABEn 147 Properties of AB Materials  Learning Outcomes Lesson 5.3 Rheological Flow Properties of AB Materials Differentiate the rheological properties of plastic and viscous materials. Discuss the d...

Lesson 5.3 Rheological Flow Properties of AB Materials ABEn 147 Properties of AB Materials  Learning Outcomes Lesson 5.3 Rheological Flow Properties of AB Materials Differentiate the rheological properties of plastic and viscous materials. Discuss the different flow behavior models describing the flow behavior of plastic and viscous materials. DEPARTMENT OF AGRICULTURAL AND BIOSYSTEMS ENGINEERING  Viscosity It is defined as the resistance of a fluid to flow. DEPARTMENT OF AGRICULTURAL AND BIOSYSTEMS ENGINEERING  Flow of materials DEPARTMENT OF AGRICULTURAL AND BIOSYSTEMS ENGINEERING  Newton’s Law of Viscosity Experimental results show that the force required to maintain the motion of the lower plate per unit area is proportional to the velocity gradient, and the proportionality constant, µ, is the viscosity of the fluid: DEPARTMENT OF AGRICULTURAL AND BIOSYSTEMS ENGINEERING  Newton’s Law of Viscosity Experimental results show that the force required to maintain the motion of the lower plate per unit area is proportional to the velocity gradient, and the proportionality constant, µ, is the viscosity of the fluid: DEPARTMENT OF AGRICULTURAL AND BIOSYSTEMS ENGINEERING  Sample Problem Two parallel plates are 0.1 m apart. The bottom plate is stationary while the upper one is moving with a velocity V. The fluid between the plates is water, which has a viscosity of 1 cp. (a) Calculate the momentum flux necessary to maintain the top plate in motion at a velocity of 0.30 m/s. (b) If water is replaced with a fluid of viscosity 100cp, and momentum flux remains constant, find the new velocity of the top plate. DEPARTMENT OF AGRICULTURAL AND BIOSYSTEMS ENGINEERING  Sample Problem DEPARTMENT OF AGRICULTURAL AND BIOSYSTEMS ENGINEERING  Sample Problem Two parallel plates are 0.1 m apart. The bottom plate is stationary while the upper one is moving with a velocity V. The fluid between the plates is water, which has a viscosity of 1 cp. (a) Calculate the momentum flux necessary to maintain the top plate in motion at a velocity of 0.30 m/s. Ans. shear stress = 0.003Pa (b) If water is replaced with a fluid of viscosity 100cp, and momentum flux remains constant, find the new velocity of the top plate. Ans. v = 0.003m/s DEPARTMENT OF AGRICULTURAL AND BIOSYSTEMS ENGINEERING Flow of materials Newtonian Fluids Dilatant Fluids A non-Newtonian fluid where the shear viscosity increases with applied shear stress. Bingham Plastics Fluid remains rigid when the magnitude of shear stress is smaller than the yield stress (𝛕0) but flows like a Newtonian fluid when the shear stress exceeds 𝛕0. Pseudoplastic Fluids In contrast to a Bingham fluid, a pseudoplastic fluid is a fluid that increases viscosity as force is applied. Thixotropic and Rheopectic Behavior What about blood? Viscosity Measurements 1. Capillary Flow Viscometers 2. Orifice Type Viscometers 3. Falling Ball Viscometers 4. Rotational Viscometers a) Concentric Cylinder (Coaxial Rotational) Viscometers b) Cone and Plate Viscometers c) Parallel Plate Viscometers d) Single-Spindle Viscometers (Brookfield Viscometer) 5. Other Types of Viscometers 1. Vibrational (Oscillation) Viscometer 2. Bostwick Consistometer Capillary Flow Viscometer Orifice Type Viscometer Falling Ball Viscometer Rotational Viscometer Other Types Vibrational (Oscillation) Viscometer Other Types Bostwick Consistometer Thank you, and see you next meeting! Engr. Jucel Marie Guatlo