5% - eTheses Repository - University of Birmingham

A0fl0 = 1.25V-0.33G-0.005 (7)
and for the upper line
03 (8)
when fitted through values of V from 0.0335m/s to 0.161m/s and
G from O.Olm/s to 0.04m/s. The numerical results and values
predicted by these equations are shown in figures 7 and 8.
Notice in figure 7 that varying the growth rate G has very little
effect on the location of the lower transition line over the
range studied. We add here that the two terms not including V
are at maximum 30% of the value for A 0R0 , even when V is at the
lower end of the range that we studied, and only 5% at the upper
end.
Figure 8 shows the fit for the upper transition line at various
G and V, and again the fit is good even though V does not appear
in the equation. The weak dependence upon V and G for the upper
and lower lines respectively allows us to ignore their respective
contributions as a first approximation.
4 DISCUSSION
Points of interest discussed below include (section 4.1) dominant
forces in each of the three regions of parameter space and
(section 4.2) the likely implications for modelling of sandwaves,
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