1 / 24

entc 303: announcements

What is a Fluid?. How does a fluid differ from a solid?. What is a Fluid?. a: displacementz, x>>h (this allows for 1D consideration). shear stress. G=shear modulus (material property). deformation. FOR A SOLID!. What is a Fluid?. For a fluid

MikeCarlo
Download Presentation

entc 303: announcements

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

    1. ENTC 303: Announcements Yes, we will have labs next week

    3. What is a Fluid?

    4. What is a Fluid?

    5. Viscosity

    6. Viscosity Kinematic Viscosity Units: cS (centistokes) mm2/s 0.10 mm2/s to 70,000 mm2/s

    7. Newtonian and Non-Newtonian Fluids Rheology: Study of the deformation and flow characteristics of fluids Two types of fluids: Newtonian and Non-Newtonian:

    8. Newtonian and Non-Newtonian Fluids

    9. Newtonian Fluids Water Oil Gasoline Alcohol Kerosene Benzene Glycerine

    10. Non-Newtonian Fluids Time-independent Fluids Pseudoplastic (Blood Plasma, syrups, inks) Dilatant (Starch in water) Bingham (catsup, mustard, toothpaste) Time-dependent Fluids Electrorheological (behavior changes due to electric field, particles are present) Magnetorheological (iron powders in fluid)

    11. Viscosity MeasurementRotating Drum Viscometer

    12. Viscosity MeasurementRotating Drum Viscometer

    13. Viscosity MeasurementCapillary Tube Viscometer Capillary Tube Makes use of pressure drop to determine viscosity

    14. Viscosity MeasurementCapillary Tube Viscometer

    15. Viscosity MeasurementFalling Ball Viscometer Viscosity is determined by noting the amount of time a ball takes to travel between two lines

    16. Viscosity MeasurementFalling Ball Viscometer

    17. Viscosity MeasurementSaybolt Universal Viscometer Ease of fluid flow through orifice is an indication of viscosity Measurement is not based on definition of viscosity Results are relative, so a standard sample is used for calibration Fast and easy

    18. Saybolt Viscosity Saybolt Equations: (cS) = 0.226t - 195/t, t< 100 SUS (cS) = 0.220t – 135/t, t> 100 SUS t, amount of time (seconds, SUS, Saybolt Universal Seconds) it takes for 60 cm3 to flow through orifice (Saybolt viscometer)

    21. Hydraulics Fluids for Fluid Power Systems Fluid Power Pneumatics: air-type systems Hydraulics: liquid-type systems Hydraulic Fluids: Petroleum oils Water-glycol fluids High water based fluids (HWBF) Silicone fluids Synthetic oils

    22. Characteristics of Hydraulic Fluids Adequate viscosity Lubricating capability Cleanliness Chemical stability Non-corrosiveness Ability to resist growth of bacteria Ecologically acceptable Low compressibility

    23. Hydraulic Fluids HWBF Fire resistant ~40% oil in water Water-glycol fluids Fire resistant 35 to 50% water

    24. Hydraulic Fluids Petroleum Oils SAE 10 W, SAE 20-20W (W means rated at maximum viscosity and cold temperatures) Engine oils Additives are required to avoid growth of bacteria Silicone Fluids For high temperature applications

More Related