WEEK 6: Researching Vehicle Types and Efficiencies

This week I researched into the efficiencies of vehicles and components they typically use. I found out that vehicle mass, aerodynamics and mechanical efficiency play a major role in the energy a vehicle uses, which determines the range, speed and acceleration a vehicle can achieve.
Once a vehicle is at a constant speed, the main force pushing back the car is air resistance, which is the energy the car needs to maintain its speed. Also mechanical rolling and transmission inefficiencies have to be overcome.

In summary, I found that a vehicle should be as light as possible, ideally around 1000 kg's or less, that has a small frontal area to reduce air resistance and has no driveshaft (most front mount engine RWD vehicles) to reduce friction and energy losses in the vehicle to maximize range and efficiency.
These are the key points for an efficient vehicle for this more sustainable car project.

Week 5, Researching Cars and Efficiencies

Week 5

This week I got my Gantt chart up and running to help with time management.
My aim was to get research done on the efficiencies and motor types in cars to begin into the design process next week.

This is a section of my research on different types of engines for cars.
I looked into the main engine types here:

• Petrol
• Diesel
• CNG
• LPG
• Electric
• Hydrogen Fuel Cell
• Electric Hybrid Petrol/Diesel

As talked over previously, petrol and diesel engines aren’t great in terms of being environmentally friendly and energy efficient, therefore I will cross them off this list.

CNG (compressed natural gas) engines are propelled by using high pressure methane in place of gasoline, working similarly to standard internal combustion engines but producing fewer undesirable gases compared to gasoline engines. This makes them slightly better for sustainability but still achieving similar efficiencies to petrol engines, therefore this sort of fuel is not the best for an environmentally friendly vehicle.

LPG (Liquid petroleum gas) engines run on a mixture of propane and butane (a flammable hydrocarbon gas mix). Although this is a cleaner burning mix for an internal combustion engine, it still produces CO2 and the only benefit really is its cheap cost. Therefore its efficiency and environmental impact are similar to gasoline engines, therefore this fuel is not the best in terms of emissions and sustainability.

Hydrogen Fuel Cell are also similar to gasoline engines however they run on a hydrogen fuel instead of petrol. The workings are the same, however the hydrogen burnt produces water vapour (H2O) as its product, therefore no harmful emissions are produced. The workings are similar but the fuel is compressed hydrogen gas. This can be bought at only some places but is mostly made by water electrolysis which can produce a hydrogen oxygen (HHO) gases. This however takes more time and energy to produce the gas and burn it than a car to run straight of electricity to its motor. It is a sustainable source of energy but takes more energy to make the gas before it being used as a fuel so this type of engine isn't the best in efficiency, also storage of the compressed gas can be tricky.

Electric Hybrid Vehicles use a combination of electric and gasoline engines to power the vehicle. There are many different ways to doing this. This could use an electric motor with batteries and a petrol generator for extra range; a petrol and electric motor with batteries for propulsion; an electric motor vehicle with battery that charges from regenerative brakes and petrol generator, etc.

These vehicles are designed to be used on electricity and petrol, so they more effective in terms of sustainability and efficiency, however, they still burn fuel and produce emissions, but far less than a traditional gasoline car. These sorts of vehicles are typically good for commuting small trips on electrical energy and longer trips on petrol engines as they require more range. For the requirements of this project, a small car for only small trips would not require the gasoline engine. Although hybrid vehicles are a good choice for many, they are probably not the best option for a very environmentally friendly vehicle for small commuting trips.

All electric vehicles run off an electric motor, powered by batteries that can be charged externally. The efficiency of the system is high with good batteries, controls and a good motor. A regenerative braking function can allow mechanical brakes to be used sparingly and electricity to be reused by converting the cars motion back to electrical energy. In New Zealand, over 80% of power is produced by renewable energy. This is a bonus in terms of sustainability as the energy that goes into the electric car is clean and is used efficiently, let alone there are no greenhouse gases produced.

There are only some downsides that all electric cars require more batteries and space to achieve the same range as a petrol car, they also have to be charged off a source of electricity, which can take a long time if only charged off a standard outlet, but the charging rate can be increased using a dedicated powerful charging station. Other than that, they are much quieter with a better performance and immediate starting torque from 0 rpm.

Electric cars are developing quickly in the modern world as their benefits for environmental issues and sustainability as well as their smooth riding ability and efficiency greatly outweigh their negatives.