2.1 The graph of log CD vs log Re

Some experimental values of CD for spheres in fluid flows at various Reynolds numbers, Re, are:


  relist = {.05875, .1585, .4786, 3.020, 7.015, 15.49, 57.54,
        144.5, 264.9, 512.9, 1000., 1862., 3162., 
        4764., 8375., .1556 10^5, .2648 10^5,
        .3467 10^5, .5888 10^5, .1000 10^6, .1702 10^6,
        .2317 10^6, .2648 10^6, .2710 10^6, .2851 10^6,
        .3020 10^6, .3388 10^6, .3981 10^6, .5129 10^6,
        .1778 10^7, .2291 10^7, .5012 10^7};
  cdlist = {492.0, 169.8, 58.88, 10.86, 5.623, 3.388,
        1.479, .9204, .7194, .5623, .4786, .4365, .4074,
        .3890, .3981, .4395, .4571, .4775, .4732, .4624,
        .4395, .4046, .3733, .3467, .2472, .1778, .1047,
        .09772, .1000, .1778, .1862, .1862};

Taking the logarithms of these numbers,


  logrelist = Log[10, relist]
  logcdlist = Log[10, cdlist]

Now we plot the graph.


  regrid[xmin_, xmax_] := Range[Floor[xmin],Floor[xmax], 1];
  cdgrid[xmin_, xmax_] := Range[Floor[xmin],Floor[xmax], 0.2];
  logplot = ListPlot[Table[{logrelist[[i]], logcdlist[[i]]},
            {i,32}],
            PlotJoined -> True,
            AxesLabel -> {"log Re", "log CD"},
            AxesOrigin -> {-2., -1.},
            AspectRatio -> Automatic,
            GridLines -> {regrid, Automatic}];
  

Up to 2. The Graph of the Drag Coefficient verses Reynolds Number