Instructions for Rheology Study Experiment

Stress versus shear rate data for honey and for mayonnaise are in the Experiment C folder on Canvas. Be sure to use the data obtained during your observation of the process. Plot the data as shown on page 9 (stress versus shear rate) of the Basic Rheology pdf file on Canvas. For honey, which is Newtonian, the plot should be linear with the slope equal to the viscosity. Calculate the viscosity (or let Excel do it for you). Do a little Google or literature searching and see if you can find a value for the viscosity of honey to which to compare your calculated value.

For the case of mayonnaise, viscosity is not constant with shear rate. As shown in Figure (b) on page 9 of the pdf file, because mayonnaise is a shear-thinning fluid, the viscosity should decrease with increasing shear rate. Create a third column in the spreadsheet where the values in the first column are divided by the corresponding values in the second column, and plot this column of numbers versus shear rate. Does the viscosity behave similarly to what is shown in Figure (b)? See if you can find any "literature" plots of the rheological behavior of mayonnaise to compare with your experimental plot.

For the purposes of your report, treat this as though you had done the work yourself with the intent of reporting on the rheological behavior of these fluids. It is not necessary, however, to include a Procedure section except perhaps to say that the data were obtained using a TA Instruments model DHR3 rheometer. The other sections of your report as they have been written for this course (Summary, Introduction, Results, Discussion, Analysis of Error, References) should be present.

Note that I have provided only the Excel spreadsheet output as that is all you should need for data analysis, and Excel should be available on any university computer. Sahar also saved the data in Trios format. As she mentioned during the demonstration, Trios is the software provided by TA Instruments that both controls the apparatus as well as displays and allows manipulation of the data. It is available as a free download from the TA Instruments website (www.tainstruments.com, click on Support, then Software Downloads and Support, then select TRIOS Software from the left-side menu). But be aware that the file to be downloaded is about 600 MB in size. If you want to try downloading this software, installing it, and using it, let me know, and I will send you the Trios data file.

Attachment:- Assignment.rar