Aerodynamics/hydrodynamics

Before last year, my main bike was a Giant Defy Advanced with a triangular down tube. When it rained, the flat bottom of the down tube forced water coming off the front wheel to depart to the sides at almost a 90 degree angle, ensuring that shoes were soaked in the rain. Last year, I picked up an old steel Miyata with traditional round tubes. I wondered how the water distribution would be and finally got a chance to find out last weekend. Two major differences stuck out, first the water coming off the front tire is more likely to "wrap" around the round down tube and then run down and drip off the bottom bracket. Secondly, the airflow around the steel bike leads to way more droplets of water hitting the legs. Not sure if this is a function of turbulent airflow around the frame or if the flat down tube prevented it by not allowing water into the frame triangle space.