🗊Презентация Power Requirements of A Vehicle

Power Requirements of A Vehicle P M V Subbarao Professor Mechanical Engineering Department

Animal Driven Vehicles

Cycle Work to be done by an Engine Directly Powering the Vehicle

Modern Cars are not Directly Driven!?!?!

High Way Driving Cycle

Urban Driving Cycle

Forces To be Overcome by an Automobile

Resistance Forces on A Vehicle The major components of the resisting forces to motion are comprised of : Acceleration forces (Faccel = ma & I forces) Aerodynamic loads (Faero) Gradeability requirements (Fgrade) Chassis losses (Froll resist ).

Aerodynamic Force : Flow Past A Bluff Body Composed of: Turbulent air flow around vehicle body (85%) Friction of air over vehicle body (12%) Vehicle component resistance, from radiators and air vents (3%)

Aerodynamic Resistance on Vehicle

Aerodynamic Drag on An Accelerating Vehicles

Purpose, Shape & Drag

Shape & Components of Drag

Some examples of Cd: The typical modern automobile achieves a drag coefficient of between 0.30 and 0.35. SUVs, with their flatter shapes, typically achieve a Cd of 0.35–0.45. Notably, certain cars can achieve figures of 0.25-0.30, although sometimes designers deliberately increase drag in order to reduce lift. 0.7 to 1.1 - typical values for a Formula 1 car (downforce settings change for each circuit) 0.7 - Caterham Seven at least 0.6 - a typical truck 0.57 - Hummer H2, 2003 0.51 - Citroën 2CV over 0.5 - Dodge Viper 0.44 - Toyota Truck, 1990-1995

0.42 - Lamborghini Countach, 1974 0.42 - Lamborghini Countach, 1974 0.42 - Triumph Spitfire Mk IV, 1971-1980 0.42 - Plymouth Duster, 1994 0.39 - Dodge Durango, 2004 0.39 - Triumph Spitfire, 1964-1970 0.38 - Volkswagen Beetle 0.38 - Mazda Miata, 1989 0.374 - Ford Capri Mk III, 1978-1986 0.372 - Ferrari F50, 1996 0.36 - Eagle Talon, mid-1990s 0.36 - Citroën DS, 1955 0.36 - Ferrari Testarossa, 1986 0.36 - Opel GT, 1969 0.36 - Honda Civic, 2001 0.36 - Citroën CX, 1974 (the car was named after the term for drag coefficient) 0.355 - NSU Ro 80, 1967

0.34 - Ford Sierra, 1982 0.34 - Ford Sierra, 1982 0.34 - Ferrari F40, 1987 0.34 - Chevrolet Caprice, 1994-1996 0.34 - Chevrolet Corvette Z06, 2006 0.338 - Chevrolet Camaro, 1995 0.33 - Dodge Charger, 2006 0.33 - Audi A3, 2006 0.33 - Subaru Impreza WRX STi, 2004 0.33 - Mazda RX-7 FC3C, 1987-91 0.33 - Citroen SM, 1970 0.32064 - Volkswagen GTI Mk V, 2006 (0.3216 with ground effects) 0.32 - Toyota Celica,1995-2005 0.31 - Citroën AX, 1986 0.31 - Citroën GS, 1970 0.31 - Eagle Vision 0.31 - Ford Falcon, 1995-1998 0.31 - Mazda RX-7 FC3S, 1986-91 0.31 - Renault 25, 1984 0.31 - Saab Sonett III, 1970 0.30 - Audi 100, 1983 0.30 - BMW E90, 2006 0.30 - Porsche 996, 1997 0.30 - Saab 92, 1947

0.195 - General Motors EV1, 1996 0.195 - General Motors EV1, 1996 0.19 - Alfa Romeo BAT Concept, 1953 0.19 - Dodge Intrepid ESX Concept , 1995 0.19 - Mercedes-Benz "Bionic Car" Concept, 2005 ([2] mercedes_bionic.htm) (based on the boxfish) 0.16 - Daihatsu UFEIII Concept, 2005 0.16 - General Motors Precept Concept, 2000 0.14 - Fiat Turbina Concept, 1954 0.137 - Ford Probe V prototype, 1985