Hi.
I have uploaded my copy here: http://folk.ntnu.no/arntovf/chung.xls . I believe I once found it at biketechreview. There is data on it from a test I did last year.
I see in the OP that you mention a flat loop and constant speed as important for this method. This is true for 'normal' aero testing (curvefitting power to speed for a range of test runs at various speeds), but for the Chung method you fit the power and speed data to to the elevation changes on the loop you ride. Consequently, you should have some variation in speed (but no braking!) and elevation on the loop to ensure a robust data set.
I have uploaded my copy here: http://folk.ntnu.no/arntovf/chung.xls . I believe I once found it at biketechreview. There is data on it from a test I did last year.
I see in the OP that you mention a flat loop and constant speed as important for this method. This is true for 'normal' aero testing (curvefitting power to speed for a range of test runs at various speeds), but for the Chung method you fit the power and speed data to to the elevation changes on the loop you ride. Consequently, you should have some variation in speed (but no braking!) and elevation on the loop to ensure a robust data set.