Investigation on Aerodynamic forces on a Horse Carriage Towing used in Brunei Darussalam

The aerodynamics of a car towing a load is an interesting problem in fluid mechanics. Since the above is both shape and flow dependant and no complete theory is available.As such, experimental techniques are thought to be useful to look into the aerodynamics of such a problem. In Brunei Darussalam, the type of horse carriage is towed normally by certain type Ford Ranger (FR) four-wheel drive car. A scale model of 1:32 of the above is made to test in a subsonic 292 mm x 292 mm wind tunnel. The ford ranger and ford ranger with horse carriage (HC) was tested separately in the above mentioned wind tunnel. The drag (CD), lift (CL) and the side forces (CS) coefficients are computed with angle of attack (α) from 0° to 30° and Reynolds Number (Re) of 1.77 x 104 to 7.08 x 104. It is well known that CD plays an important role in fuel economy. As expected CD for towing is generally higher than the CD for isolated car for all the above investigated ranges of α and Re. To reduce CD a modification on the body shape was suggested and tested in the wind tunnel. The modified body shape reduced CD to a minimum of 20% and a maximum of 53% for α = 0° in the investigated ranges of Re.