Now, how do you do this, how do we know the existence of laminar flow on a model? It can be easily got, obtained from the model experiment itself. If I have plotted Rn here and CT here, I know my CF line is like this and one plus k CF line is this; and mind you laminar flow will mostly occur at low speed, because the speed is low, Reynolds number is very low, if we actually go for high speed, laminar flow may be suppressed by large extent- depends on model scale. Now, here, we have seen that the resistance curve should have been like this that is, at low speeds it should follow this line when there is no CR and then it goes like this; it may so happen you will find that the resistance curve is actually going like this or even coming down to this line, even going below the CF at low speeds, then you know something is wrong here and the reason for this will be laminar flow.