Sökning: "vortex drag"
Visar resultat 21 - 25 av 30 avhandlingar innehållade orden vortex drag.
21. Investigation on Propeller-Rudder Interaction by Numerical Methods
Sammanfattning : The axial forces in a propeller-rudder interactive system working in uniform flow are theoretically studied: In a steady linear method the propeller is represented by bound and free vortex systems, the rudder by vortex and source filaments and the rudder wake by free vortex filaments. A lifting-line analysis method predicts the propeller characteristics. LÄS MER
22. Investigation of Wheel Housing Flow on Heavy Trucks
Sammanfattning : Increasing fuel prices and demands for reductions of emissions have led to a considerably increased interest in developing more efficient vehicles. Besides designing more efficient power units with lower fuel consumption and emission levels it is possible to increase the total efficiency of the vehicle by aerodynamic optimization. LÄS MER
23. Unsteady Numerical Simulations of Flow around Heavy Vehicles, Trains and Passenger Cars
Sammanfattning : In this thesis several simulations have been carried out aimed at improving the knowledgeof vehicle aerodynamics and improving the flow around vehicles with respect to theaerodynamic drag. Four flows around different simplified vehicles have been considered. LÄS MER
24. Unsteady Numerical Simulations and Reduced-Order Modelling of Flows around Vehicles
Sammanfattning : In this thesis several simulations have been carried out aimed at improving the knowledge of vehicle aerodynamics and improving the flow around vehicles with respect to theaerodynamic drag. Five flows around different simplified vehicle models have been considered in five appended publications. LÄS MER
25. Numerical Simulations of Flows around Trains and Buses in Cross Winds
Sammanfattning : When cruising in strong winds, ground vehicles can experience strong aerodynamic forces and moments that may increase drag, reduce their stability, generate noise and induce accidents in the case of strong side winds. However, prevention of the unwanted influences of side winds requires that the flow structures around vehicles are fully understood in both the instantaneous and time-averaged flow. LÄS MER