Introduction
In the world of automotive engineering, every aspect of vehicle performance is optimized to deliver the best driving experience. While engine power, aerodynamics, and suspension systems often dominate discussions on performance, one crucial element significantly influences the overall dynamics and safety of a vehicle - Tyres.
Automotive designers have to balance various factors such tyre wear, rolling resistance and road grip to achieve optimum vehicle performance. Notably, a vehicle's behavior is strongly influenced by Tyre–road interaction and is linked to complex phenomena within tyre contact patches. This in turn translates to fuel efficiency, speed and better vehicle handling. The tyre needs to be designed according to optimized requirements with respect to footprint pressure and shape, wear, rolling resistance, durability as well as tyre characteristics (forces, moments). Thus, the intention is to give a general overview on the current challenges in tyre simulation and prospects with Quantum algorithm especially in advanced tyre simulation in order to show the benefits for the design process.
Vehicle Features that can be enhanced through Tyre Simulation:
Enhancing Vehicle Dynamics: Tyre simulation improves vehicle dynamics by accurately modeling Tyre behavior, allowing engineers to optimize handling and performance.
Ensuring Safety through Simulation: Tyre simulation helps develop advanced safety systems by understanding how a vehicle responds in different situations, reducing the risk of accidents and enhancing occupant safety.
Maximizing Fuel Efficiency: Tyre simulation optimizes fuel efficiency by analyzing Tyre designs and properties to minimize rolling resistance and energy consumption, reducing CO2 emissions and saving on fuel costs.
Minimizing Noise and Vibration: Tyre simulation evaluates factors contributing to noise and vibration, enabling manufacturers to optimize Tyre designs for a quieter and more comfortable ride.
Reducing Development Costs and Time: Tyre simulation identifies performance issues, enables design changes in virtual testing, reduces the need for physical prototyping and iterative testing, saves on costs, and accelerates time-to-market for improved vehicles.
The growing need to mimic interaction between the vehicle and the external environment under various conditions needs advanced simulation technology. Automotive manufacturers demand tyres that are precisely targeted to their needs. With the rise of EVs and the increase in electric variants, tyres that can bear the increased weight while reducing rolling resistance need to be developed.
Reducing rolling resistance:
Figure: Schematic of a tyre during rolling resistance test over dry sand
Rolling resistance is crucial in analyzing the longitudinal mechanical properties of tyres. It is calculated based on the total viscoelastic energy loss per rolling distance when traveling at the maximum stable speed. Several factors contribute to rolling resistance, including rubber hysteresis, road conditions, tyre pressure, load, speed, and tread design. Studies indicate that tread patterns significantly affect pneumatic tyres' rolling resistance but minimally impact solid tyres. Tread depth and contact area are crucial contributors to rolling resistance, with increased contact areas reducing rolling resistance but increased tread depth resulting in higher resistance. Optimizing tyre designs can lead to reduced rolling resistance and increased energy efficiency, hence, showing the need for advanced simulation tools to optimize tyre designs.
Advanced Simulations allows engineers to evaluate key factors like tread design, tyre compound, construction, inflation pressure, and surface contact, vital for reducing rolling resistance in tyres. Optimizing these parameters enhances tyre efficiency and minimizes energy loss.
Multiphysics models for better insights
As vehicle complexity continues to grow, the need for multiphysics models in simulations becomes crucial for gaining better insights.
Multiphysics models consider the interactions between multiple physical phenomena, such as fluid dynamics, thermodynamics, structural mechanics, and electromagnetics. Accurately simulating these interactions, solving complex equations, and performing numerous computations can significantly increase computational requirements and time.
However, these models can be computationally expensive and time-consuming to run.
BQP’s Simulation of Things approach tackles tough computational challenges by leveraging advanced quantum algorithms to speed up the modeling of intricate physical systems accurately.
Different Multiphysics simulations approach
In order to replicate real-world situations, the tyre–road interaction models play a fundamental role in-vehicle system modeling. Tyres are responsible for generating forces arising within the tyre-road contact patches linked to vehicle handling and ride/comfort phenomena. Accordingly, it pertains to several modeling approaches to replicate tyre–road interaction.
Mechanical modeling: Mechanical modeling helps accurately predict longitudinal and lateral forces, and self-aligning torque, considering factors such as Tyre pressures, camber angles, wheel loads, speeds, track conditions, and ambient temperatures. It enables engineers to optimize Tyre performance under diverse operating conditions. Some mechanical models that are used in tyre simulation are briefly discussed.
Tyre physics models:
String Model: The string model simplifies the Tyre carcass as a stretched chord, representing the tyre's tension and lateral resilience. It is used for studying steering wheels and aircraft landing gear.
Beam Model: The beam model improves upon the string model by considering the carcass as an infinite-length beam on an elastic basis. It gives better results for simple maneuverability analysis and can reflect the deformation physics of the tyre.
Brush Model: The brush model assumes an elastic tread and a rigid carcass. It is simulated using a three-dimensional elastic brush unit and is characterized by fast computation speed. It is commonly used in control and stability analysis and can analyze the relationship between lateral force, side angle, and longitudinal slip.
Finite Element Model: The finite element model provides a detailed description of the tyre's geometric characteristics and material properties using discrete units connected by nodes. It can simulate any complex structure and load and has been widely used to analyze various Tyre characteristics, such as inflatable shape and stress, load-displacement curve, and contact problems.
Thermodynamic model:
The thermodynamic model analyzes Tyre thermal behavior regarding interactions with the external environment and inner wheel chamber. It describes thermodynamic evolution and, therefore, thermal behavior using the Fourier diffusion equation in a three-dimensional domain while considering the external environment, interactions, and the inner wheel chamber.
The model considers various physical phenomena such as heat generation from friction and strain energy loss, heat exchange with the external environment (thermal conduction and convection), and heat conduction between Tyre nodes due to temperature gradient. The model requires input data such as tyre forces, Tyre slip, longitudinal velocities, rotation frequencies, inclination angles, and vehicle forward speed to evaluate temperatures and inner pressure.
Topology Optimization
As applied to Tyre design, topology optimization powered by quantum algorithms can significantly improve Tyre performance and durability. The influence of reinforcement turn-up on various Tyre parameters using finite element analysis (FEA). For example, adjusting the height of the bead reinforcement turn-up can optimize the radial and lateral stiffness of the tyre. Hence, it is enhancing its overall performance. Critical design factors must be controlled during manufacturing to prevent fatigue and failure. For instance, through FEA, designers can accurately analyze stress and strain conditions, enabling them to make informed decisions and improve tyre durability and operating characteristics.
Topology optimization, with FEA, offers a predictive technology that guides designers in optimizing Tyre designs for the efficiency and longevity of vehicles. Topology optimization powered by a quantum algorithm, in conjunction with FEA, can guide designers in minimizing the Tyre reinforcement turn-up effect. Fine-tuning design parameters, such as the height of reinforcement turn-up, Tyre durability, radial stiffness, lateral stiffness, and cornering behavior, can significantly be improved, leading to safer and more efficient tyres.
Benefits of integrating Quantum Algorithms for Tyre simulations.
Tyres are complex inflated structures that make them difficult to model analytically. Due to this modeling complexity, finite element (FE) based models, String models, Beam models, and Brush models are challenging and computationally heavy. They are making it a concern for the efficiency and reliability of Tyres. In real-world applications, it is essential to account for pre-tension force, inflation pressure, and two- and three-dimensional parameters. These are making it more complex and challenging to solve using classical algorithms on classical computers. These coupled and multi-objective simulation problems fall short in computing resources when using classical algorithms on classical computers.
Contrary to classical, quantum algorithms exploit quantum principles like superpositions and entanglements; these algorithms solve optimization problems more efficiently even with fewer computing resources. Accordingly, this approach is offering a better way for engineers to solve Tyre simulation problems.
BQP's Simulation of Things approach combines quantum algorithms to solve simulation problems with fewer computational resources. It has shown remarkable efficiency while delivering more optimized designs than traditional classical approaches.
As vehicles continue to evolve and push the boundaries of performance, Tyre simulation will remain an indispensable component of the automotive engineering process. Its role in shaping the vehicles of the future is pivotal, and its impact will continue to drive advancements for safer, more efficient, and even more exhilarating driving experiences.