Yazar "Drugge, Lars" seçeneğine göre listele
Listeleniyor 1 - 5 / 5
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Assessment of a Two Equation Eddy-Viscosity Turbulence Model in Crosswind Simulation of a Heavy Ground Vehicle(Sae Int, 2022) Tunay, Tural; Drugge, Lars; O'Reilly, Ciaran J.The present study assesses the use of a two-equation eddy-viscosity turbulence model, which is a shear-stress transport (SST) k-omega turbulence model, in two-way coupled aerodynamics and vehicle dynamics simulation of a heavy ground vehicle subjected to crosswind. The obtained results are compared with the corresponding results of the improved delayed detached-eddy simulation (IDDES) conducted at similar conditions from the previous literature. The aim is to evaluate the effects of different turbulence models used in aerodynamics simulations to resolve the vehicle dynamics results in two-way coupled simulations. The results present that the absolute relative percent differences between the lateral displacement, yaw angle and roll angle results of the SST k-omega and the IDDES simulations are less than 1%, 3%, and 10%, respectively. As for the aerodynamics results, the absolute relative percent differences between the lateral force, yaw moment, and roll moment of the SST k-omega and the IDDES simulations are less than 7.3%, 8.5%, and 10.0%, respectively. The results also show that the magnitudes of the lateral force, roll moment, and yaw moment are mostly increased due to the crosswind excitations among all other force and moment components. The yaw moment presents the fastest response to the crosswind excitations.Öğe On coupling methods used to simulate the dynamic characteristics of heavy ground vehicles subjected to crosswind(Elsevier, 2020) Tunay, Tural; Drugge, Lars; O'Reilly, Ciaran J.Ground vehicles often encounter turbulent flows with wide range of scales, e.g. crosswind gusts, when moving on-road conditions. Crosswinds can be considered as an important factor in heavy vehicle's roll-over accident due to their relatively high center of gravity and lateral surface area. However, there are few studies which investigate effects of crosswinds on heavy vehicles. Furthermore, existing studies have generally focused on lateral or yaw dynamics of heavy vehicles and neglected their roll dynamics. Therefore, effects of crosswinds on heavy ground vehicles should be understood in all aspects in order to design less wind-sensitive vehicles especially at early stages of their design processes. Inherently, crosswind studies require a multidisciplinary approach which involves coupling between aerodynamics and vehicle dynamics. In the present study, investigation of effects of the coupling methods, e.g. one-way and two-way couplings, between aerodynamics and vehicle dynamics simulations are aimed by considering both lateral and roll dynamics of heavy vehicles which are subjected to crosswind gust. Vehicle dynamics and aerodynamics results are presented. Results of the one-way coupled simulations, in general, overestimate the absolute maximum values of the vehicle dynamics results. However, differences in lateral displacement results Delta y(max) are less than 0.2 m for the studied case.Öğe The Effects of Different Drivers' Steering Inputs on the Response of Heavy Ground Vehicles to Crosswind Disturbances(Mdpi, 2024) Tunay, Tural; Drugge, Lars; O'Reilly, Ciaran J.Featured Application The control, stability, or even safety of a vehicle can be influenced by crosswinds. The findings of the current study can be helpful for the reliable design of ground vehicles with less wind sensitivity early in their development processes. The development of lateral disturbance compensation algorithms and autonomous vehicles can also benefit from the results of the study.Abstract The general approach in the previous studies was to ignore the driver's steering contribution to a vehicle while investigating the interactions between crosswind and vehicle. Therefore, the goal of this study is to find out how steering inputs by drivers affect a heavy-ground vehicle's dynamic reaction to crosswinds. In the investigation, a two-way interaction between vehicle dynamics and aerodynamic simulations was employed. The steering inputs of drivers were modelled using a driver model taken from the previous literature that is able to reproduce the steering responses of a human driver. The study's findings demonstrated that the steering inputs made by drivers significantly impacted how the vehicle responded to crosswinds. For instance, the greatest lateral displacement of the least skilled driver (Driver 1) was around 1.53 times the greatest lateral displacement of the most skilled driver (Driver 3) at the delay time of t delta,delay = 0.5 s in the steering input. Additionally, the maximum lateral displacement results of Driver 1 and Driver 3 at t delta,delay = 1.0 s became 1.39 and 1.56 times greater than their maximum lateral displacement results at t delta,delay = 0.5 s. Similarly, the total steering inputs of Driver 1 and Driver 3 at t delta,delay = 1.0 s were 1.4 and 2.2 times greater than their total steering inputs at t delta,delay = 0.5 s, respectively. In general, the results of a driver who is more skilled than Driver 1 (Driver 2) fall in between the respective results of Driver 1 and Driver 3. On the other hand, each driver's total steering inputs at t delta,delay = 0.5 s were roughly the same as their total steering inputs at t delta,delay = 0 s. In all delay scenarios for the start of the driver's steering inputs, the drivers' steering inputs amplified the yaw moment applied to the vehicle. Meanwhile, they diminished the lateral force and roll moment.Öğe The Significance of Roll on the Dynamics of Ground Vehicles Subjected to Crosswind Gusts by Two-Way Coupled Simulation of Aero- and Vehicle Dynamics(Springer International Publishing Ag, 2020) Tunay, Tural; O'Reilly, Ciaran J.; Drugge, LarsImprovements in vehicle technologies in recent decades enable the use of lighter materials and the development of control systems for autonomous vehicles. However, these improvements lead to a need for better understanding of how flow phenomena affect crosswind stability of ground vehicles which will enable the design of the less wind-sensitive vehicles. Therefore, the present study investigates the significance of roll on the dynamics of ground vehicles subjected to crosswind gusts. It includes a multidisciplinary approach in which there is a two-way coupled simulation between aerodynamics and vehicle dynamics equations. As a result of the investigations, significant differences have been found between the computations considering no-roll and roll motions.Öğe Two-Way Coupled Aerodynamics and Vehicle Dynamics Crosswind Simulation of a Heavy Ground Vehicle in Winter Road Conditions(Springer Science and Business Media Deutschland GmbH, 2022) Tunay, Tural; Drugge, Lars; O’Reilly, Ciarán J.The present study investigates the dynamic characteristics of a heavy ground vehicle that is subjected to crosswind on winter roads by two-way coupled simulations of aerodynamics and vehicle dynamics. Three different road friction coefficients, ? = 1.0, 0.3 and 0.15, were investigated, representing dry, snowy, and icy road conditions, respectively. Results show that the lateral displacements of the vehicle on the icy road are 13%, 20% and 26% more than the corresponding lateral displacements of the vehicle on the dry road at maximum crosswind velocities of w cw,max = 3.5 m/s, 4.5 m/s and 5.5 m/s, respectively. Additionally, at w cw,max? 4.5 m/s and a crosswind length of three times the vehicle length, corresponding to the reduced frequency of k = 2.1, the crosswind might cause the driver to lose control of the vehicle, causing it to cross the road’s lateral margins in all road conditions which could result in an accident. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.
