Better fuel economy to reduce global warming

In this article of The Guardian, it states that six changes to fuel economy can have a major impact on the reduction of global warming. The first is reducing the fuel economy on trucks, which have a huge fuel consumption compared to the amount of vehicles in traffic. Fleet operators need to become aware of the problem and act accordingly. Secondly, other fuel sources have to be made commercially viable. Right now, there are barely any electricity loading places (or for other fuels) present and increasing them would increase the use of alternative resources. Further, there is also the need to make the numbers more objective. At the moment, different studies have been done, isolated from others. This makes is immensely hard to compare them. BSR also tries to implement a tool for the better investigation of life-cycle assessment. Making a better life-cycle assessment will improve the possibility of comparing different fuel resources, materials used etc. They also think that the future is not one kind of clean fuel, but a cooperation of the fuels, because all the alternative fuels have different disadvantages. And lastly, it is important to act now, because we’re close to the limit of contaminants in the atmosphere and waiting will only increase the risk of not reversible damage.

Which of these changes do you think is more important? Or do you think that only when all changes are applied at the same time, it will have a positive effect?



Rough ship surfaces may reduce global warming

Better aerodynamics reduce fuel consumption, and thankfully, car manufacturers work on aerodynamics for the European market. But fuel economy is not only important for land vehicles. As we know, it’s very important for aircraft, but also water vessels should improve their fuel economy. A lot of fuel is used for cargo transport by ships, but if we can improve their hydrodynamics, we can reduce their fuel consumption.

One way of reducing their fuel consumption, is off course reducing their drag. This can be done by making their surfaces more rough. This is contrary to our intuition, but this study done by the UCLA proves that the right sort of roughness can reduce the friction drag of the ships. This will reduce the fuel consumption and that will in turn reduce the global warming.

I think that a lot of research has to be done on fuel economy for ships, but should there also come some sort of regulation about the fuel consumption, like there is for cars now?


Air, not a problem but a gift? – The wind turbine

The previous blogs were all about the fight against air. How can we make our object aerodynamically as efficient as possible. How can we deal with air as a certain resistance?
But air isn’t always a negative medium as it can be used in advance.
Climate change and the fight against it has become a major topic in modern society. The effects of global warming are clearly visible and people are aware that things need to change concerning energy consumption. Already several years ago we saw the start up of ‘green’ energy. The research for new concepts like the electric car, biofuel, but also green electricity were born.

An example of green electricity is the wind turbine. A wind turbine transfers the kinetic energy of the wind into electrical power. A concept which is already quite old, but the first electricity-generating turbine was made in 1887 by James Blyth and was a battery charging machine.
The first utility grid-connected wind turbine however showed up in 1951.

Nowadays wind turbines are a common view in the modern landscape. Off shore and on shore there are already several windfarms. The largest wind farm, called the Gansu Wind Farm in China, has even a capacity of 6000 MW which is even more then the total capacity of nuclear energy in Belgium.

It’s clear that wind turbines can replace nuclear energy, but the biggest downside is the fact that you need to have an enormous area to reach a capacity which is meaningful. The design of the rotor plays an important role in this story about the efficiency of the wind turbine. According to the law of the physicist Albert Betz only 58.3% of the wind energy could be transformed into electrical power.
But due to the design of the rotor modern turbines can even reach an efficiency of 70-80%.

Do you think it is realistic that wind turbines would replace nuclear energy? Do you also know phenomena which can be negative for us but on the other side useful, like wind energy?
For me I think it is not realistic that wind turbines alone would control the electrical grid in Belgium.
Nuclear energy is still far more efficient if you look to the waste/profit ratio. Don’t understand me wrong, I am not totally pro nuclear energy, but I think there needs to be another technology to replace the nuclear energy because wind turbines are too unpredictable concerning constant grid capacity.


Methods of solving aerodynamic problems: Wind tunnel vs CFD

The most commonly known method in testing the behaviour of air around an object is trough wind tunnel testing. The first wind tunnel was already build in 1871 by Frank H. Wenham, a council member of the Aeronautical Society of Great Britain. It was not the first device for measuring the aerodynamic forces this was the whirling arm. However this device had several disadvantages because the object was moving in it’s own wake due to the centrifugal forces.

During world war two the largest wind tunnel of that time was built at Wrigth Field in Ohio. The wind tunnel was 14m long and had a diameter of 6.1m. The air was produced due to two 12m large fans driven by a 40000 hp electric. It was a huge progression because large scale aircrafts could be tested at speeds of 640 km/h.

Nowadays wind tunnels are more integrated in technological research centres. There are several companies who have their own wind tunnel for example Mercedes, but because of the high cost it is not affordable for every company.

This leads us to the domain of CFD (Computational Fluid Dynamics).  This method is a branch of fluid mechanics. It uses numerical methods in solving fluid equations like the Navier Stokes equations. It started in 1910 where the calculations were done by hand which led to 2000 iterations per week.
But along with the technological evolution of computers, CFD technology improved a lot. Because of more computational power better results could be achieved and at a higher rate.

In 1985 CFD found his way to the well known “aero” industries like Boeing.
In 1995 CFD was also used for “non-aero” applications like GM, Ford, …

Today CFD is integrated in every company which does aerodynamic research.
It is a relative quick method for having a first impression on what will happen with the body due to the aerodynamic forces. It gives a full domain analyses, easy alternative analyses, it is way cheaper and has a better visualisation of results. The biggest disadvantage of CFD is the fact that it can be erroneous in certain situations, but those situations are mostly well known phenomena. For this reason it is also advised that the software is used by experienced modellers. On the other hand it is not an accepted industry standard. It can only be used on projects which aren’t too complex.

The big question is: Would CFD completely wash away wind tunnel testing in the feature?
Are there other domains where practical experiments are on the edge of being defeated by software?

I think CFD will win the battle in the end. It can defeat the wind tunnel in a few years. But for most of the objects tested in wind tunnels there is large list of safety rules like an aeroplane for example. For this reason I think real modelling with a wind tunnel will always exist, because people won’t take the risk in not simulating the real world.

Aerodynamics vs esthetics

This week, our teacher explained in class that trucks are aerodynamically horrible. Those who understand aerodynamics at least a bit, will agree. But attempts have been made (for a long time already) to reduce the drag of trucks. These trucks have a tremendously reduced drag (sometimes up to 50%), but they are ugly. Therefore no company buys these trucks and they keep the trucks with the old design. Since trucks (and buses) take up a huge amount of fuel consumption and pollution, aerodynamics are very important for them, however no improvements are made. The only improvements are the ones on direct fuel economy like better engines and electric engines.

Part of the problem is off course that the aerodynamic trucks are still more expensive than the original ones. Maybe if the government subsidises the aerodynamic trucks, things might change.

I think that although the aerodynamic trucks are more expensive in investment, they will eventually be cheaper because the reduced operating costs. Especially if you consider that trucks generally drive quite long, you can see many deteriorated trucks in operation.

Do you think maybe a subsidy from the government, or a penalty for using the old design should be used? Or is there another better solution?

Here’s an image of the aerodynamic truck:

Public transportation satisfaction

Last time we discussed the rebound effect of fuel economy, amongst others the public transportation system. I found this article about the (dis)satisfaction of public transportation and the effects of it on public transportation use. In the article, it states that a good follow-up on the (dis)satisfaction of public transportation and the implementation of solutions against dissatisfaction are a good way to increase the overall utility of public transportation. Satisfied customers will spread word of mouth and will attract new customers while dissatisfied customers will decrease the amount of customers.

Because people are different, public transportation has to be differentiated as well. Privatization and deregulation seem very efficient in increasing the satisfaction of customers and can be expected to increase the utility of public transportation. This increased utility of public transportation can then have an effect on the car usage policy.

I believe that cooperation between public transport services (bus/train/metro/…) is at least partly the clue to a better satisfaction of customers. Off course, accuracy of public transportation will be an issue as well, but with customer satisfaction, the utility of public transportation will go up and the personal vehicle use will go down. How big the effect will be is uncertain off course, but every little bit helps. If we can also implement solutions like car-free-zones, a lot of pollution can be prevented and the environment will benefit from it greatly.


Aerodynamics and scientific ignorance

In the last few years research in aerodynamics has come to a higher level. This can be seen in several domains. For example in the automobile sector where more standard cars ar equipped with a small sportive spoiler at the back and subtile front and rear diffuser. When riding on a highway and paying attention to the small spoiler at the back of the car you will notice that already several standard cars have this aerodynamic improvement (fig 1).

Rear spoiler Blog post

There are also several other industries were aerodynamics has become of great importance, the modern racebike industry for example. Where aerodynamics is one of the several aspects in development concerning cars, aerodynamics has become one of the major topics in improving modern race bikes. One thing I already mentioned in my preveous blog.

But along with this aerodynamic research a lot of rumors and scientific misunderstandigs are spread into the world of the amateuristic cyclists. For example the introduction of high rimmed 80mm aerowheels a few years ago. Most of the professional cycling teams rode with them. This led to the fact that those wheels were bought massivly by the amateuristic rider. But a few months later we already so that there were almost no riders in the peloton anymore who rode with the high aerowheels. This because of the fact that the aerodynamic gain of the wheels is less compared with the weight difference you can get with lower rims of 40mm/32mm. As a matter of fact the wheels have there advantages but only having their full potential when speeds higher then 40km/h are reached, which is quite optimistic for an amateur rider to reach constant speeds like this.

On the other side according to the following table:

We see that the aero helmet can even gain a higher reduction of the drag then aerowheels and cost you 10 times less. But still those things are bought by the amateuristic rider. Offcourse the peloton is the best promo for bike manufacturers and part suppliers. But shouldn’t the manufacturers give more information about the purpose, advantages and disadvantages of their products? For example, if we look to Paris-Roubaix a few years ago most of the riders rode with these high aero wheels made out of carbon. Riding with super lightweight aerowheels made out of carbon on some of the worst cobblestones in the world? No, those wheels will maybe last for one ride, but are definitely aren’t made fort his purpose. But still amatueristic riders think those wheels are good for these circumstances with the result that a lot of these wheels just crack which leads to waste.

I think the amateuristic rider should be more informed about the performance of bike equipment available to them.

What do you think? Should marketing be more honest about the technical part of their product?