Paper Title :Aerodynamic Performance of a Forward Bent Frame in a High Speed Bike

Author :Paritosh Prakhar, Musfera S. Javed

Article Citation :Paritosh Prakhar ,Musfera S. Javed , (2016 ) " Aerodynamic Performance of a Forward Bent Frame in a High Speed Bike " , International Journal of Mechanical and Production Engineering (IJMPE) , pp. 27-34, Volume-4,Issue-10

Abstract : With growing demand for transportation medium with minimum fuel consumption and maximum efficiency, often the most economical medium is overlooked i.e. a bicycle. A bicycle is one of the most primitive yet one of the most efficient mode of transport with the 97% power transmission efficiency. A design with double reduction chain drive transmission system claims to attain speeds as high as 300 km/h at practical cadence of 130 rpm. However the aerodynamic stability of such a bike with a conventional frame is a questionable issue. Moreover the human body itself is not designed to counter such high air flow velocities on its ventral side. The large ventral area combined with the very small lateral area leads to formation of low pressure zones as well as vortices behind the dorsal surface which tends to increase the overall drag while bending the upper torso to counter this drag leads to the generation of a lift force on the body of the ride. Moreover the bending of upper torso still leaves the lower part of the body to attack the air in the same way as an upright body. Thus, an aerodynamically stabilized frame that can reduce the drag forces without causing an uplift is a desirable venture. Here, a frame design where the seating position is kept ahead of the pedaling shaft is proposed, i.e. the entire body from the feet to the head lie in along a curve to minimize air drag along with uplift forces. The designing of the frame was initiated with a simulation of the conventional frame under high speed conditions (speeds above 100km/h). The wheel speed has been taken into account while doing the simulation. The simulations were be carried out in moderate axial wind. The overall research is aimed at the creation of a bicycle design that is aerodynamically efficient at speeds higher than the motorized bikes and thus offers an alternative to the fast gasoline powered bikes as well as to the slow human powered vehicles (battery powered). Index Terms— Air Drag, Cadence, Dorsal Surface, Uplift, Ventral Area, Vortices

Type : Research paper

Published : Volume-4,Issue-10

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