pressure measurement in the test system
pressure measurement in the test system
(OP)
Hi Friends,
Could you give some information about this problem. I work on polymer processing and I have a simple test system. This system consist of heated reservoir and a piston. Polymer is filled in reservoir and heated when is melted. then polymer flows through small hole. In this system, pressure value is read a constant point in the reservoir. My problem is that pressure value is continuously drop at this point. I know that pressure should drop in reservoir but I dont understand why pressure value is different at the constant point using a constant piston speed.
If you give suggestion I will be pleased.
Could you give some information about this problem. I work on polymer processing and I have a simple test system. This system consist of heated reservoir and a piston. Polymer is filled in reservoir and heated when is melted. then polymer flows through small hole. In this system, pressure value is read a constant point in the reservoir. My problem is that pressure value is continuously drop at this point. I know that pressure should drop in reservoir but I dont understand why pressure value is different at the constant point using a constant piston speed.
If you give suggestion I will be pleased.





RE: pressure measurement in the test system
Many other fluid and flow classifications describing various shear stress vs distance between layers characteristic curves exist such as Bingham Plastics, (toothpaste, clay, asphalts, tomato ketchup, or is it catsup or catchsup?), pseudoplastics (grease, soap, paint, latex, paper pulps), dilatant (quicksand) and thixotroic fluids (paints, greases, asphalts, inks). Non-Newtonian fluids can have shear rate values that change with their rate of movement or even over time alone. Many crude oils can have curve values that can change with only how long they have been sitting in a tank before pumping. Could this be it?
For more info, see page 19 of this Power Point Presentation,
http://
http://virtualpipeline.spaces.msn.com
RE: pressure measurement in the test system
Thank you BigInch but my problem is a bit different. I know non-newtonian flows viscosity change with shear rate values but in this test system piston speed is constant and pressure transducer read continuosly different pressure value at same point not different point.
RE: pressure measurement in the test system
http://virtualpipeline.spaces.msn.com
RE: pressure measurement in the test system
I am sure that velocity of piston don't change during the test because piston is mounted a tensile/compression machine. Only force values are changing in the machine screen. :(