Abstract In the automotive industry, optimizing the vehicle\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\'s aerodynamic performance is important because it affects speed, acceleration, stability, controllability, fuel consumption, and environmental pollution. In this numerical research applying Ansys Fluent software, the effects of using air ducts in different areas of front and rear of the body in a Sedan car was investigated. The purpose is to investigate aerodynamic coefficients by transferring airflow from higher-pressure areas to lowerpressure areas around the car body to attain a general viewpoint of their performance. The results showed the appropriate effect of aerodynamic forces in all models. In the front aerodynamics modification, the most decrease in drag coefficient occurred by connecting the front bumper to the front wheelhouse by 10.5%, while the most decrease in lift coefficient was 16.5% when the flow was transferred to the hood. In the rear aerodynamics modification, by transferring airflow from the rear wheelhouse to the rear bumper, the drag coefficient was reduced by 16% and the lift coefficient was reduced by 16.5%

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