A bicycle wheel rim for assembly with a plurality of spokes includes a wheel rim body having two opposite annular sidewalls, an annular intermediate wall connected between the sidewalls, and an annular rib connected between the sidewalls opposite to the intermediate wall. The control device has a pair of sleeves, a positioner, a resilient element, a push-button, a driving element, a string. The housing has a penetration cavity in the middle thereof, and a wire loading an alternating current thereon passes through the penetration cavity. Other embodiments are described and claimed. The isolation and combination of impingement openings provides for the augmentation of convection and film cooling and provide the flexibility to tailor airflow on an airfoil to optimize thermal performance of an airfoil. The pocket is sealed to a foil cover which connects to the second body portion.