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Aerodynamic devices, such as wings, are used in higher levels of motorsport (Formula-1 etc.) to increase the contact force between the road and tyres (i.e. to generate downforce). This in turn increases the performance envelope of the race car. However the extra downforce increases aerodynamic drag which (apart from when braking) is generally detrimental to lap-times. The drag acts to slow the vehicle, and hinders the effect of available drive power and reduces fuel economy. Wings, in automotive use, are not constrained by the same parameters as aircraft, and thus higher angles of attack can be safely reached, although at a higher cost in drag. Variable geometry aerodynamic devices have been used in many forms of motorsport in the past offering the ability to change the relative values of downforce and drag. These have invariably been banned, generally due to safety reasons. The use of active aerodynamics is currently legal in both Formula SAE (engineering compet ition for university students to design, build and race an open-wheel race car) and production vehicles. A number of passenger car companies are beginning to incorporate active aerodynamic devices in their designs. In this research the effect of ground proximity on the lift, drag and moment coefficients of inverted, two-dimensional aerofoils was investigated. The purpose of the study was to examine the effect ground proximity on aerofoils post stall, in an effort to evaluate the use of active aerodynamics to increase the performance of a race car. The aerofoils were tested at angles of attack ranging from 0° - 135°. The tests were performed at a Reynolds number of 2.16 x 105 based on chord length. Forces were calculated via the use of pressure taps along the centreline of the aerofoils. The RMIT Industrial Wind Tunnel (IWT) was used for the testing. Normally 3m wide and 2m high, an extra contraction was installed and the section was reduced to form a width of 295mm. The wing was mounted between walls to simulate 2-D flow. The IWT was chosen as it would allow enough height to reduce blockage effect caused by the aerofoils when at high angles of incidence. The walls of the tunnel were pressure tapped to allow monitoring of the pressure gradient along the tunnel. The results show a delay in the stall of the aerofoils tested with reduced ground clearance. Two of the aerofoils tested showed a decrease in Cl with decreasing ground clearance; the third showed an increase. The Cd of the aerofoils post-stall decreased with reduced ground clearance. Decreasing ground clearance was found to reduce pitch moment variation of the aerofoils with varied angle of attack. The results were used in a simulation of a typical Formula SAE race car.

Aerodynamic devices, such as wings, are used in higher levels of motorsport (Formula-1 etc.) to increase the contact force between the road and tyres (i.e. to generate downforce). This in turn increases the performance envelope of the race car. However the extra downforce increases aerodynamic drag which (apart from when braking) is generally detrimental to lap-times. The drag acts to slow the vehicle, and hinders the effect of available drive power and reduces fuel economy. Wings, in automotive use, are not constrained by the same parameters as aircraft, and thus higher angles of attack can be safely reached, although at a higher cost in drag. Variable geometry aerodynamic devices have been used in many forms of motorsport in the past offering the ability to change the relative values of downforce and drag. These have invariably been banned, generally due to safety reasons. The use of active aerodynamics is currently legal in both Formula SAE (engineering compet ition for university students to design, build and race an open-wheel race car) and production vehicles. A number of passenger car companies are beginning to incorporate active aerodynamic devices in their designs. In this research the effect of ground proximity on the lift, drag and moment coefficients of inverted, two-dimensional aerofoils was investigated. The purpose of the study was to examine the effect ground proximity on aerofoils post stall, in an effort to evaluate the use of active aerodynamics to increase the performance of a race car. The aerofoils were tested at angles of attack ranging from 0° - 135°. The tests were performed at a Reynolds number of 2.16 x 105 based on chord length. Forces were calculated via the use of pressure taps along the centreline of the aerofoils. The RMIT Industrial Wind Tunnel (IWT) was used for the testing. Normally 3m wide and 2m high, an extra contraction was installed and the section was reduced to form a width of 295mm. The wing was mounted between walls to simulate 2-D flow. The IWT was chosen as it would allow enough height to reduce blockage effect caused by the aerofoils when at high angles of incidence. The walls of the tunnel were pressure tapped to allow monitoring of the pressure gradient along the tunnel. The results show a delay in the stall of the aerofoils tested with reduced ground clearance. Two of the aerofoils tested showed a decrease in Cl with decreasing ground clearance; the third showed an increase. The Cd of the aerofoils post-stall decreased with reduced ground clearance. Decreasing ground clearance was found to reduce pitch moment variation of the aerofoils with varied angle of attack. The results were used in a simulation of a typical Formula SAE race car.

O objetivo básico deste trabalho era verificar e quantificar o efeito coanda quando aplicado a um ambiente de atmosfera estagnada na qual a velocidade do escoamento livre é igual a zero. Um aparelho constituído da combinação de um motor e uma hélice combinados com um revestimento externo originalmente utilizado como um componente básico em um túnel de vento experimental. Uma seção de contração de madeira foi projetada e construída para ser unida logo à frente do conjunto hélice/motor, formando um jato retangular. Um aerofólio de seção constante foi testado, formando um jato retangular. Um aerofólio de seção constante foi testado, fixado imediatamente à frente do escoamento do bocal de saída, utilizando uma envergadura igual à largura do jato do bocal de saída. Foram feitas medições do perfil do limite do jato sobre uma distância que excede aquelas incluindo (ambas) as medidas da corda (conhecida do aerofólio). O perfil de velocidade do escoamento induzido sobre a superfície superior de um aerofólio de seção NASA GA(w)-1 foi tomado para um aerofólio limpo e com uma faixa com rugosidade num ponto próximo ao bordo de ataque. O aerofólio foi testado com e sem a faixa de rugosidade, com pontos de tomada de pressão estática ao longo de sua corda fornecendo assim sua distribuição de pressão. O aerofólio foi testado para ângulos de ataque entre zero a quarenta e cinco graus referentes à ilha do escoamento do jato. Os resultados foram registrados e analisados conseqüentemente. / The basic objective of this work was to verify and quantify the Coanda Effect when applied to a stagnent atmosphere in which the free stream velocity was zero. An apparatus consisting of a motor and fan combination combined with external fairings originally used in an experimental wind tunnel was used as the basic component. A wooden contraction section was designed and built to be joined immediately downstream of the fan/motor combination, providing a rectangular jet. A constant section airfoil was tested, suspended immediately downstream of the outlet mouth using a span length equal to that of the mouth of the jet. Measurements were made of the jet limit profile over a distance that exceeded that including the aerofoil chord. The velocity profile induced by the jet flow over the upper surface of a NASA GA(W)-1 section aerofoil was measured for the clean one and with a roughness strip in place near the leading edge. The aerofoil was tested with chordwise static pressure points along the centerline giving the respective pressure distribution, also with and without a roughness strip added. There were different tests for angles of attack with reference to the jet centerline between zero and forty five degrees. The results were registered and analysed accordingly.

O objetivo básico deste trabalho era verificar e quantificar o efeito coanda quando aplicado a um ambiente de atmosfera estagnada na qual a velocidade do escoamento livre é igual a zero. Um aparelho constituído da combinação de um motor e uma hélice combinados com um revestimento externo originalmente utilizado como um componente básico em um túnel de vento experimental. Uma seção de contração de madeira foi projetada e construída para ser unida logo à frente do conjunto hélice/motor, formando um jato retangular. Um aerofólio de seção constante foi testado, formando um jato retangular. Um aerofólio de seção constante foi testado, fixado imediatamente à frente do escoamento do bocal de saída, utilizando uma envergadura igual à largura do jato do bocal de saída. Foram feitas medições do perfil do limite do jato sobre uma distância que excede aquelas incluindo (ambas) as medidas da corda (conhecida do aerofólio). O perfil de velocidade do escoamento induzido sobre a superfície superior de um aerofólio de seção NASA GA(w)-1 foi tomado para um aerofólio limpo e com uma faixa com rugosidade num ponto próximo ao bordo de ataque. O aerofólio foi testado com e sem a faixa de rugosidade, com pontos de tomada de pressão estática ao longo de sua corda fornecendo assim sua distribuição de pressão. O aerofólio foi testado para ângulos de ataque entre zero a quarenta e cinco graus referentes à ilha do escoamento do jato. Os resultados foram registrados e analisados conseqüentemente. / The basic objective of this work was to verify and quantify the Coanda Effect when applied to a stagnent atmosphere in which the free stream velocity was zero. An apparatus consisting of a motor and fan combination combined with external fairings originally used in an experimental wind tunnel was used as the basic component. A wooden contraction section was designed and built to be joined immediately downstream of the fan/motor combination, providing a rectangular jet. A constant section airfoil was tested, suspended immediately downstream of the outlet mouth using a span length equal to that of the mouth of the jet. Measurements were made of the jet limit profile over a distance that exceeded that including the aerofoil chord. The velocity profile induced by the jet flow over the upper surface of a NASA GA(W)-1 section aerofoil was measured for the clean one and with a roughness strip in place near the leading edge. The aerofoil was tested with chordwise static pressure points along the centerline giving the respective pressure distribution, also with and without a roughness strip added. There were different tests for angles of attack with reference to the jet centerline between zero and forty five degrees. The results were registered and analysed accordingly.

Computational Fluid Dynamics (CFD) is a main field that contributes to the development of high efficiency aircraft. CFD accuracy depends on the flow solver and the meshing of the geometry, and while it is doable to determine why a certain solver is more accurate than another, it is much more difficult to discern why two meshes produce differently accurate solutions. A framework is presented to evaluate the performance or ``goodness" of a mesh and to compare meshes. The framework is composed of quantifiable mesh parameters which define a mesh, and three performance measures: functional accuracy, their order of convergence, and their behaviour under the adjoint correction method. Although it seems that the relationships between parameters and results are not trivial, there are trends from which optimal mesh parameters are deduced. The H topology performs best, and the most important parameters are related to spacings and cell quality around the aerofoil leading edge.