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Nowadays, the shortage of fossil fuels and the effects of their consumption on the environment make it necessary to optimize the aerodynamics of vehicles in order to minimize fuel consumption and CO2 emissions. This is the reason why this project studies the aerodynamics of the generic DrivAer model, adding passive devices to reduce its aerodynamic drag and therefore fuel consumption and CO2 emissions. The model chosen to carry out the study is the fastback DrivAer with smooth underbody, and the simulation conditions are without moving ground nor wheel rotation. The Reynolds with which the simulations have been performed is 4.87M, using the RANS method with the k-omegaSST turbulence model. The model has been validated with an error of less than 4% by comparing the results with other experimental and numerical studies. The passive control elements added to the base geometry are a rear low spoiler configuration and two deltashaped vortex generators configurations, one placing 11 units in parallel and the other placing 10 pairs of vortex generators tilted 15 degrees right and left consecutively with respect to the car’s plane of symmetry. The rear spoiler reduces drag by 7% and the set of vortex generators up to 2%. With both mechanisms applied to the car, the aerodynamic drag reduction achieved is 7.5%.

During the last few years and especially due to the fact that climate change has become a reality, the automotive industry has been trying to adapt. Typical petrol engines seem to be near their end, and research on electric cars and hydrogen cars is being carried out, all of it with the purpose of emissions reduction. At this point is where drag reduction, or aerodynamic efficiency gathers importance, being one of the most important forces that a car has to overcome and as a result, becoming key in car design. Drag reduction can be obtained in different ways, from smooth designs to the use of active and passive control flow devices such as vortex generators, air curtains, spoilers, etc. This is the point from where the current project emerges, aiming to be able to prove the efficiency of these devices. This project then focuses on an efficiency study via CFD simulation of three types of passive control flow device: the Vortex Generator, the Spoiler and the Rear Wing. The first step that has been done is the simulation of a baseline case, using the DrivAer Notchback. In this way, 6 different configurations of devices have been compared to the benchmark case by adding them to the baseline case geometry. The configurations tested are: Two different Vortex Generators iterations, a spoiler, a rear wing and two more configurations of Vortex Generators + Spoiler. The results have made clear that not all the configurations and neither all the devices are good for drag reduction, obtaining a reduction in the Cd of 1,6 % for one of the Vortex Generators cases but also an increment of 15 % for the rear wing case.

During this last decade, automotive industry has been focusing on the efficiency of the cars. The fuel consumption regulations, combined with the range of electric cars, have set a critical design factor: fuel consumption. Among all the design areas involved, aerodynamics take a great role in that objective, as more aerodynamic elements are added to everyday cars in order to reduce drag, making cars more efficient. One component that car manufacturers are starting to include is the air curtain, located in the car’s bumper, with different configurations depending on the car manufacturer. In this work, a study of these air curtains will be carried out, from the design of two configurations based on real geometries, to its aerodynamic behaviour to finally understand if their implementation indeed improves the vehicle’s aerodynamic performance against drag, also known as aerodynamic resistance.

From this last ten years on, the last trend of the automotive industry has been to produce daily driver cars as efficient as possible. This decision has permitted aerodynamic performance to be one of the most important aspects in a car’s development. From slender designs, through the implementation of splitters or diffusers and right up to deployable spoilers at certain speeds, there are multiple aerodynamic components. However, when this elements are mentioned, nobody thinks of vortex generators, those geometries located on the car’s roof, usually with a shark fin design. At first, one could think they only are used as covers, while the reality is far from that. In this work, a study of these vortex generators will be carried out, from the design of several geometries to its aerodynamic behaviour, to finally understand if their implementation is purely aesthetic or if they indeed improve the vehicle’s aerodynamic performance

The introduction of the Harmonized Light Vehicles Test Procedure causes a significant challenge for the automotive industry, as it increases the importance of efficient aerodynamics and demands how variations of optional extras affect the car’s fuel consumption and emissions. This may lead to a huge number of combinations of optional extras that may need to be aerodynamically analyzed and possibly optimized, being to resource-consuming to be done with wind tunnel testing merely. Reynolds Average Navier-Stoles (RANS) coupled with Large Eddy Simulations (LES) have shown potential for accurate simulation for automotive applications for reasonable computational cost. In this paper, three hybrid RANS-LES models are investigated on the DrivAer notchback and fastback car bodies and compared to wind tunnel measurements. Several yaw angles are investigated to see the model’s ability to capture small and large changes of the flow field. It is seen that the models generally are in good agreement with the measurement, but only one model is able to capture the behavior seen in the measurements consistently. This is connected to the complex flow over the rear window, which is important to capture for accurate force predictions.

Táto diplomová práca sa zameriava na numerickú simuláciu modelov vozidla DrivAer s rôznymi tlakovými stratami chladiča. Pre jednotlivé typy chladičov sú vytvorené CFD modely vozidla v karosárskej verzií Estate, spolu s chladičom a zjednodušeným motorovým priestorom. Cieľom práce je porovnanie vlastností konvenčného hliníkového chladiča s vlastnosťami prototypu polymérového chladiča a ich vplyv na aerodynamický odpor vozidla., This diploma thesis focuses on numerical simulation of DrivAer vehicle model with different pressure losses of the radiator. CFD models of the vehicle in Estate body version for individual type of riadiator are created, together with a radiator and a simplified engine compartment. The aim of this work is to compare characteristics of conventional aluminium radiator with characteristics of polymeric prototype radiator and their impact on aerodynamic drag of the vehicle.

Táto diplomová práca sa zaoberá CFD výpočtom aerodynamických charakteristík vozidiel idúcich za sebou, vytvorených v programe Star CCM+. Sleduje hlavne ich aerodynamické odpory v závislosti na rôznych rozostupoch medzi vozidlami a vyhodnocuje, ktoré vzdialenosti sú energeticky najvýhodnejšie pre vozidlá ako celok. Následne popisuje postup, ako z týchto údajov vypočítať spotrebu paliva pre jednotlivé rozostupy., This thesis deals with CFD simulation of platooning vehicles and their aerodynamic characteristics, created in Star CCM+ software. The main focus is on their aerodynamic drag dependency on different spacing between vehicles which allowed to evaluate the most energy efficient distance for platoon of vehicles. Furthermore, the procedure how to calculate the fuel consumption is described for set of variables.

Táto diplomová práca sa zameriava na numerickú simuláciu modelov vozidla DrivAer s rôznymi tlakovými stratami chladiča. Pre jednotlivé typy chladičov sú vytvorené CFD modely vozidla v karosárskej verzií Estate, spolu s chladičom a zjednodušeným motorovým priestorom. Cieľom práce je porovnanie vlastností konvenčného hliníkového chladiča s vlastnosťami prototypu polymérového chladiča a ich vplyv na aerodynamický odpor vozidla., This diploma thesis focuses on numerical simulation of DrivAer vehicle model with different pressure losses of the radiator. CFD models of the vehicle in Estate body version for individual type of riadiator are created, together with a radiator and a simplified engine compartment. The aim of this work is to compare characteristics of conventional aluminium radiator with characteristics of polymeric prototype radiator and their impact on aerodynamic drag of the vehicle.

Táto diplomová práca sa zaoberá CFD výpočtom aerodynamických charakteristík vozidiel idúcich za sebou, vytvorených v programe Star CCM+. Sleduje hlavne ich aerodynamické odpory v závislosti na rôznych rozostupoch medzi vozidlami a vyhodnocuje, ktoré vzdialenosti sú energeticky najvýhodnejšie pre vozidlá ako celok. Následne popisuje postup, ako z týchto údajov vypočítať spotrebu paliva pre jednotlivé rozostupy., This thesis deals with CFD simulation of platooning vehicles and their aerodynamic characteristics, created in Star CCM+ software. The main focus is on their aerodynamic drag dependency on different spacing between vehicles which allowed to evaluate the most energy efficient distance for platoon of vehicles. Furthermore, the procedure how to calculate the fuel consumption is described for set of variables.

Diplomová práce je zaměřena na CFD simulaci jízdy skupiny dvou za sebou jedoucích vozidel DrivAer v různých karosářských variantách. Pro karosářské varianty Estateback, Fastback a Notchback jsou vytvořeny CFD modely, které jsou následně řešeny pomocí turbulentního modelu k-epsilon. Cílem práce je analýza vlivu zadní části karoserie vozů na jejich aerodynamické charakteristiky s ohledem na jízdu ve skupině., This diploma thesis is focused on CFD simulation of two platooning DrivAer cars with varying bodyworks. CFD models are made for bodywork variants Estateback, Fastback and Notchback, which are solved by k-epsilon turbulent model. Influence of rear body design on platooning and aerodynamics characteristics is analyzed.

Tato diplomová práce se zabývá modelováním a CFD výpočtem aerodynamických charakteristik variant vozidla, ovlivněných zatíženými a nezatíženými pneumatikami a dále vlivem na pneumatiky aplikovaných okrajových podmínek. Tyto výpočty kombinuje pro tři typy variabilní karoserie zádi vozidla DrivAer. Je zde provedena kompletní analýza a zhodnocení vlivů daných činitelů., This diploma thesis deals with modeling and CFD calculation of aerodynamic characteristics of vehicle, influenced by loaded or unloaded tires and boundary conditions applied on this tires. These calculations are combined with three types of variable rear body shape of DrivAer vehicle. There is a complete analysis and evaluation of the effects of these factors.

Táto diplomová práca sa zaoberá CFD výpočtom aerodynamických charakteristík vozidiel idúcich za sebou, vytvorených v programe Star CCM+. Sleduje hlavne ich aerodynamické odpory v závislosti na rôznych rozostupoch medzi vozidlami a vyhodnocuje, ktoré vzdialenosti sú energeticky najvýhodnejšie pre vozidlá ako celok. Následne popisuje postup, ako z týchto údajov vypočítať spotrebu paliva pre jednotlivé rozostupy., This thesis deals with CFD simulation of platooning vehicles and their aerodynamic characteristics, created in Star CCM+ software. The main focus is on their aerodynamic drag dependency on different spacing between vehicles which allowed to evaluate the most energy efficient distance for platoon of vehicles. Furthermore, the procedure how to calculate the fuel consumption is described for set of variables.

Cieľom tejto práce je vytvoriť vhodný nástroj pre rýchle analýzy recirkulácie teplého vzduchu na chladiacom pakete, ktorá je jedným z významných faktorov vplývajúcich na jeho účinnosť, zhodnotiť tento vplyv a navrhnúť spôsoby na jeho zníženie. Teoretická časť práce sa venuje popisu problému, preskúmaniu existujúcich štúdií a priblíženiu mechanizmov, ktoré sú súčasťou sledovaného javu. Praktická časť obsahuje analýzu prúdových a tepelných javov v motorovom priestore existujúceho vozidla, ktorej výsledky slúžia ako podklad pre vytvorenie výpočtového modelu s grafickým rozhraním. Tento model je následne použitý na porovnanie vplyvov rôznych vstupných parametrov a na základe výsledkov sú navrhnuté geometrické opatrenia cielené na zníženie negatívneho efektu recirkulácie, ktoré sú vyhodnotené pomocou CFD výpočtov., The focus of this thesis is to create an effective tool for quick analyses of hot air recirculation at the cooling package, wich is a significant factor that influences its effectivity, to evaluate this influence and to propose viable solutions for its mitigation. The theoretical part of the thesis is devoted to the description of the problem, review of existing scientific studies and introducing the mechanisms responsible for the studied phenomenon. The practical part contains an analysis of flow and thermal effects, whose outputs are used for developing an computational model with a graphical user interface. This model is further used for comparison of effects of various input parameters and based on its results the measures targeted on reduction of recirculation are designed, which are then evaluated using CFD methods.

Cieľom tejto práce je vytvoriť vhodný nástroj pre rýchle analýzy recirkulácie teplého vzduchu na chladiacom pakete, ktorá je jedným z významných faktorov vplývajúcich na jeho účinnosť, zhodnotiť tento vplyv a navrhnúť spôsoby na jeho zníženie. Teoretická časť práce sa venuje popisu problému, preskúmaniu existujúcich štúdií a priblíženiu mechanizmov, ktoré sú súčasťou sledovaného javu. Praktická časť obsahuje analýzu prúdových a tepelných javov v motorovom priestore existujúceho vozidla, ktorej výsledky slúžia ako podklad pre vytvorenie výpočtového modelu s grafickým rozhraním. Tento model je následne použitý na porovnanie vplyvov rôznych vstupných parametrov a na základe výsledkov sú navrhnuté geometrické opatrenia cielené na zníženie negatívneho efektu recirkulácie, ktoré sú vyhodnotené pomocou CFD výpočtov., The focus of this thesis is to create an effective tool for quick analyses of hot air recirculation at the cooling package, wich is a significant factor that influences its effectivity, to evaluate this influence and to propose viable solutions for its mitigation. The theoretical part of the thesis is devoted to the description of the problem, review of existing scientific studies and introducing the mechanisms responsible for the studied phenomenon. The practical part contains an analysis of flow and thermal effects, whose outputs are used for developing an computational model with a graphical user interface. This model is further used for comparison of effects of various input parameters and based on its results the measures targeted on reduction of recirculation are designed, which are then evaluated using CFD methods.

Táto diplomová práca sa zameriava na numerickú simuláciu modelov vozidla DrivAer s rôznymi tlakovými stratami chladiča. Pre jednotlivé typy chladičov sú vytvorené CFD modely vozidla v karosárskej verzií Estate, spolu s chladičom a zjednodušeným motorovým priestorom. Cieľom práce je porovnanie vlastností konvenčného hliníkového chladiča s vlastnosťami prototypu polymérového chladiča a ich vplyv na aerodynamický odpor vozidla., This diploma thesis focuses on numerical simulation of DrivAer vehicle model with different pressure losses of the radiator. CFD models of the vehicle in Estate body version for individual type of riadiator are created, together with a radiator and a simplified engine compartment. The aim of this work is to compare characteristics of conventional aluminium radiator with characteristics of polymeric prototype radiator and their impact on aerodynamic drag of the vehicle.

Diplomová práce je zaměřena na CFD simulaci jízdy skupiny dvou za sebou jedoucích vozidel DrivAer v různých karosářských variantách. Pro karosářské varianty Estateback, Fastback a Notchback jsou vytvořeny CFD modely, které jsou následně řešeny pomocí turbulentního modelu k-epsilon. Cílem práce je analýza vlivu zadní části karoserie vozů na jejich aerodynamické charakteristiky s ohledem na jízdu ve skupině., This diploma thesis is focused on CFD simulation of two platooning DrivAer cars with varying bodyworks. CFD models are made for bodywork variants Estateback, Fastback and Notchback, which are solved by k-epsilon turbulent model. Influence of rear body design on platooning and aerodynamics characteristics is analyzed.

Diplomová práce je zaměřena na CFD simulaci jízdy skupiny dvou za sebou jedoucích vozidel DrivAer v různých karosářských variantách. Pro karosářské varianty Estateback, Fastback a Notchback jsou vytvořeny CFD modely, které jsou následně řešeny pomocí turbulentního modelu k-epsilon. Cílem práce je analýza vlivu zadní části karoserie vozů na jejich aerodynamické charakteristiky s ohledem na jízdu ve skupině., This diploma thesis is focused on CFD simulation of two platooning DrivAer cars with varying bodyworks. CFD models are made for bodywork variants Estateback, Fastback and Notchback, which are solved by k-epsilon turbulent model. Influence of rear body design on platooning and aerodynamics characteristics is analyzed.

Táto diplomová práca sa zaoberá CFD výpočtom aerodynamických charakteristík vozidiel idúcich za sebou, vytvorených v programe Star CCM+. Sleduje hlavne ich aerodynamické odpory v závislosti na rôznych rozostupoch medzi vozidlami a vyhodnocuje, ktoré vzdialenosti sú energeticky najvýhodnejšie pre vozidlá ako celok. Následne popisuje postup, ako z týchto údajov vypočítať spotrebu paliva pre jednotlivé rozostupy., This thesis deals with CFD simulation of platooning vehicles and their aerodynamic characteristics, created in Star CCM+ software. The main focus is on their aerodynamic drag dependency on different spacing between vehicles which allowed to evaluate the most energy efficient distance for platoon of vehicles. Furthermore, the procedure how to calculate the fuel consumption is described for set of variables.

Tato diplomová práce se zabývá modelováním a CFD výpočtem aerodynamických charakteristik variant vozidla, ovlivněných zatíženými a nezatíženými pneumatikami a dále vlivem na pneumatiky aplikovaných okrajových podmínek. Tyto výpočty kombinuje pro tři typy variabilní karoserie zádi vozidla DrivAer. Je zde provedena kompletní analýza a zhodnocení vlivů daných činitelů., This diploma thesis deals with modeling and CFD calculation of aerodynamic characteristics of vehicle, influenced by loaded or unloaded tires and boundary conditions applied on this tires. These calculations are combined with three types of variable rear body shape of DrivAer vehicle. There is a complete analysis and evaluation of the effects of these factors.

Táto diplomová práca sa zameriava na numerickú simuláciu modelov vozidla DrivAer s rôznymi tlakovými stratami chladiča. Pre jednotlivé typy chladičov sú vytvorené CFD modely vozidla v karosárskej verzií Estate, spolu s chladičom a zjednodušeným motorovým priestorom. Cieľom práce je porovnanie vlastností konvenčného hliníkového chladiča s vlastnosťami prototypu polymérového chladiča a ich vplyv na aerodynamický odpor vozidla., This diploma thesis focuses on numerical simulation of DrivAer vehicle model with different pressure losses of the radiator. CFD models of the vehicle in Estate body version for individual type of riadiator are created, together with a radiator and a simplified engine compartment. The aim of this work is to compare characteristics of conventional aluminium radiator with characteristics of polymeric prototype radiator and their impact on aerodynamic drag of the vehicle.

Táto diplomová práca sa zameriava na numerickú simuláciu modelov vozidla DrivAer s rôznymi tlakovými stratami chladiča. Pre jednotlivé typy chladičov sú vytvorené CFD modely vozidla v karosárskej verzií Estate, spolu s chladičom a zjednodušeným motorovým priestorom. Cieľom práce je porovnanie vlastností konvenčného hliníkového chladiča s vlastnosťami prototypu polymérového chladiča a ich vplyv na aerodynamický odpor vozidla., This diploma thesis focuses on numerical simulation of DrivAer vehicle model with different pressure losses of the radiator. CFD models of the vehicle in Estate body version for individual type of riadiator are created, together with a radiator and a simplified engine compartment. The aim of this work is to compare characteristics of conventional aluminium radiator with characteristics of polymeric prototype radiator and their impact on aerodynamic drag of the vehicle.

Táto diplomová práca sa zaoberá CFD výpočtom aerodynamických charakteristík vozidiel idúcich za sebou, vytvorených v programe Star CCM+. Sleduje hlavne ich aerodynamické odpory v závislosti na rôznych rozostupoch medzi vozidlami a vyhodnocuje, ktoré vzdialenosti sú energeticky najvýhodnejšie pre vozidlá ako celok. Následne popisuje postup, ako z týchto údajov vypočítať spotrebu paliva pre jednotlivé rozostupy., This thesis deals with CFD simulation of platooning vehicles and their aerodynamic characteristics, created in Star CCM+ software. The main focus is on their aerodynamic drag dependency on different spacing between vehicles which allowed to evaluate the most energy efficient distance for platoon of vehicles. Furthermore, the procedure how to calculate the fuel consumption is described for set of variables.

Táto diplomová práca sa zaoberá CFD výpočtom aerodynamických charakteristík vozidiel idúcich za sebou, vytvorených v programe Star CCM+. Sleduje hlavne ich aerodynamické odpory v závislosti na rôznych rozostupoch medzi vozidlami a vyhodnocuje, ktoré vzdialenosti sú energeticky najvýhodnejšie pre vozidlá ako celok. Následne popisuje postup, ako z týchto údajov vypočítať spotrebu paliva pre jednotlivé rozostupy., This thesis deals with CFD simulation of platooning vehicles and their aerodynamic characteristics, created in Star CCM+ software. The main focus is on their aerodynamic drag dependency on different spacing between vehicles which allowed to evaluate the most energy efficient distance for platoon of vehicles. Furthermore, the procedure how to calculate the fuel consumption is described for set of variables.

Diplomová práce je zaměřena na CFD simulaci jízdy skupiny dvou za sebou jedoucích vozidel DrivAer v různých karosářských variantách. Pro karosářské varianty Estateback, Fastback a Notchback jsou vytvořeny CFD modely, které jsou následně řešeny pomocí turbulentního modelu k-epsilon. Cílem práce je analýza vlivu zadní části karoserie vozů na jejich aerodynamické charakteristiky s ohledem na jízdu ve skupině., This diploma thesis is focused on CFD simulation of two platooning DrivAer cars with varying bodyworks. CFD models are made for bodywork variants Estateback, Fastback and Notchback, which are solved by k-epsilon turbulent model. Influence of rear body design on platooning and aerodynamics characteristics is analyzed.

Tato diplomová práce se zabývá modelováním a CFD výpočtem aerodynamických charakteristik variant vozidla, ovlivněných zatíženými a nezatíženými pneumatikami a dále vlivem na pneumatiky aplikovaných okrajových podmínek. Tyto výpočty kombinuje pro tři typy variabilní karoserie zádi vozidla DrivAer. Je zde provedena kompletní analýza a zhodnocení vlivů daných činitelů., This diploma thesis deals with modeling and CFD calculation of aerodynamic characteristics of vehicle, influenced by loaded or unloaded tires and boundary conditions applied on this tires. These calculations are combined with three types of variable rear body shape of DrivAer vehicle. There is a complete analysis and evaluation of the effects of these factors.