The data normalized in Fig. 3, shown here again for convenience used far field values for density, temperature, and the three components (u,v,w) of the velocity field, hence, normalized values for these properties are not necessarily equal to one. After the data was normalized by the far field values, the data was then scaled: the minimum value was set to "0" and the maximum value was set to "255". Assignment#3 requires that you reverse this process starting with the binary values for the u,v,w components of the velocity, and then calculate the vector sum of the normalized velocity.
Figure 3. Parameters Defined for a Compressible Mixing Layer.
As you would expect your final answer could have a value greater then one.