We are currently living in a world where inventions and discoveries are tripling by the minute. Keeping up with the latest engineering and tech news has turned out to be such a tedious task, that it is now a job for many people. And in this world, running trials for that innovation that popped up in your head is more expensive than ever. This is where ANSYS comes in. Here, we’re going to discuss how ANSYS tools could be used to make improvements in the aerodynamics of electric vehicles.
What is ANSYS?
To give you an idea about what ANSYS does, imagine that you’re trying to build an airplane out of paper that glides for a remarkable amount of time. Of course, you
can build numerous models and figure out what works and what doesn’t. But why waste so much paper when you could use ANSYS tools to create different 3D simulations of your paper airplane? ANSYS uses principles of aerodynamics to figure out what you could improve in your model to perfect it. With over 80+ simulation software, ANSYS boasts a powerful tool for your engineering needs. This article will focus primarily on ANSYS Fluent, a highly effective fluid simulation tool used to replicate the aerodynamic characteristics of the model you’re working with.
The Dynamics of Air
A very frequently asked question by children is how planes stay afloat with so many people on board. The only answer to that is aerodynamics. It studies how airflow changes as it comes in contact with a solid surface, like a bird wing.
The four factors that affect aerodynamic performance are lift, weight, thrust, and drag. Using the example of a plane, I’ll try and explain how these factors play a role in the aerodynamics of it.
Weight is the most obvious one. The lighter the body, the longer it stays afloat. Birds are experts at being aerodynamic; their hollow bones make them lightweight. Much like the buoyant force which is exerted on an object in water, the lift is an aerodynamic force that opposes gravity and keeps your plane in flight. Thrust is the aerodynamic force that pushes your plane forward. Lastly, drag is the opposing force faced by the plane in its forward movement. Lift, thrust, and drag are especially affected by the shape and structure of the plane. A streamlined object (something like a teardrop) is the most aerodynamic shape and has been the blueprint of the model of many vehicles.
Importance of aerodynamics for electric vehicles
Electric cars have taken over the market due to their higher efficiency as compared to traditional internal combustion engine cars. It has been estimated that electric cars are up to 90% efficient whereas fuel engines are only 17-21% efficient. Their major drawback is that their energy depends almost entirely on the capacity of the battery. There’s only so much energy a battery can expel. Therefore, making the car as aerodynamic as possible helps counter the amount of energy needed to propel the car. Automotive aerodynamics focuses mainly on reducing drag. It ultimately results in a better body design, as well as better fuel efficiency. As mentioned earlier, the aerodynamics of an electric vehicle can be significantly improved by making it look like a tear-drop.
There are so many components that constitute a car, which makes it quite hard to achieve that streamlined shape. Hence, it is of great importance to simulate different models of an electric vehicle in order to optimize its aerodynamics.
ANSYS Fluent is a CFD, or computational fluid dynamics software package. It means that it creates simulations of fluid flow mechanisms to optimize designs of models (like electric vehicles). With numerous in-built tools, ANSYS Fluent helps engineers figure out what needs improvement in their design of a vehicle’s model, gives an insight into fluid behavior, and helps solve complex fluid flow issues. It employs advanced mathematical methods to solve the issues related to fluid flow. The main features of this software are:
- Fluid Flow simulations: As mentioned earlier, ANSYS Fluent enables its users to create simulations to work out the aerodynamic issues that arise due to the design of their product.
- Pre-processing capabilities: This tool possesses pre-processing capabilities to be applied before you run your simulation.
- Mesh generation: ANSYS Fluent divides the geometry of the design you created into smaller discrete cells. These cells form a mesh that directly influences the simulation results.
- Multiphysics simulations: ANSYS Fluent can be used along with other ANSYS software such as ANSYS Mechanical to understand coupled phenomena, such as fluid-structure interactions.
- Post-processing and visualization: After the completion of the simulation, ANSYS Fluent gives you a wide variety of analyzing tools such as animations, contour plots, and graphical tools.
How to use ANSYS Fluent in the optimization of the aerodynamics of electric vehicles?
Although it may seem complex, ANSYS Fluent provides a user-friendly interface for your fluid flow problems while solving issues regarding the aerodynamics of electric vehicles.
Firstly, we have to decide what aspect of aerodynamics we’re trying to improve in our design. Then we create or insert the geometry of the electric car model into the software. It should accurately represent the design we’re trying to simulate. Using ANSYS Fluent’s mesh generation tools, create a high-resolution mesh that will enable you to capture the fluid flow features accurately. Define the pre-processing boundary conditions such as rate of flow, turbulence, etc. Finally, run the simulation to understand where optimization is required.
An optimization tool has to be set up after the simulation has been completed, and the required optimizations have been evaluated. This can be completely automated in ANSYS Fluent. All you have to do is define an optimization algorithm and strategy and execute the optimization loop which will run numerous simulations of your model that fall under your defined optimization constraints. Evaluate the results of the optimization loop, and continue doing so until a desirable outcome has been achieved.
This is a very oversimplified version of how you could use ANSYS Fluent to create and optimize the 3D designs of an electric vehicle. It requires rigorous training, an advanced understanding of physics and expertise in CFD to actually perform such a task.
Our world is at its highest growth rate as of now. Transportation, although it makes our lives easier, has created environmental issues. Petrol prices are rising and people are looking for a newer alternative. The emergence of electric cars was only a small step towards sustainability; we still have a long way to go. Consequently, the optimization of such electric vehicles provides an opportunity for us all to be environmentally responsible. As we have seen, ANSYS proves to be a very powerful tool that can be used to solve many engineering-related problems, and here we aimed to solve just one of them. By using its cutting-edge simulation software, it is now possible to create very aerodynamic vehicles that save energy.
As of now, we have Lightyear 0, the most aerodynamic and energy-efficient electric car in the market with a drag coefficient of 0.175. And what do you think they used to simulate their design? ANSYS of course! If that doesn’t encourage you to use ANSYS I don’t know what will.