Aerodynamics – Velomobile

Cycling is a sport with a lot of different domains, it is a very wide sports branch.
Wether you’d like to race a bike, go offroad, do tricks, jump, for each branch there is a specific bicycle developed. One of the more special bikes is the recumbent bike or Velomobile.
It is a totally different concept if you look to the general picture of a bike. The main concept however is the same, drive a drivetrain with human power.

tu delft velomobile

A few years ago the university of TU Delft, well known for their aerodynamical knowledge, started developing their own velomobile in trying to beat the world recordholder in having the fastest velomobile around. The main advantages of the velomobile is the speed increase you can gain from his aerodynamic position low to the ground.

Due to this factor much higher speeds can be gained with less human power as it would be with a normal race bike. It is no coincidence that the velomobile is based upon the geometry of a water drop which still has the lowest drag coefficient. For three years they’ve tried to beat the world record which they eventually did. They reached a topspeed of 133.78 km/h taken into account that the rider was a pro-athlete. Nevertheless this shows the speed possibilities of this strange vehicle.

In my opinion it is a great solution for people who want to go tot heir job by bike. Most of the time the distance that needs to be travelled are slightly too large for most of the people and it would take too much time. With the velomobile normal speeds of 40 km/h can be achieved easily which make it much more attractive.

This is not the only reason why it should be a good solution, another reason is being waterproof. One of the main reasons why people won’t go to work by bike is due to bad weather conditions. With the velomobile you won’t get wet!

Another reason is the position of the rider on the bike. Most of the riders of a velomobile say it is comfortable position which removes the annoying saddle pain.

On the other hand I am realistic, this is not the kind of bike you should use in an urban environment.
But on the other hand when you can ride to your work in an countryside region, along a canal for example, you can reach much furter distances in much less time.

What do you think of this transportation vehicle?


Reducing emissions

When we’re driving our car, we emit a lot of exhaust gases, one of the most dangerous being CO. Exhaust gases are usually very fine, especially with the modern vehicles. However, that gives us the problem of the fine particles. 90% of all emissions are now smaller than 1 micron (As reference, the human eye can see up to 20 micron and a human hair is 70 micron). Those fine particles get inhaled by humans and come into our respiratory system. Obviously, we have to try to reduce these harmful fine particle emissions, in order to stay healthy. There are already a few solutions available, e.g. the 3-way catalyst (which uses precious metals to transform NOx, CO and Hydrocarbons to less dangerous gases), exhaust gas redirect, etc.

Research on those exhaust gases is being done to improve the quality of the exhaust gases (i.e. reduce the harmful emissions). But just how important is this research? A lot of different researches are being done on everything from fuel to exhaust gas. Mainly the engine is given a lot of attention, but I think there should also be a lot of attention on the exhaust gases. Car manufacturers only research it because of the legislation involved.


Regenerative braking

Studies about fuel economy are all around, but with the coming of the hybrid and electric cars, other possibilities exist. You have for example regenerative braking. With a normal car, all the energy from the car is converted to heat when you brake. With regenerative braking, at least a part of that energy can be converted to useful energy (electricity). If you use a hybrid or electric car, that electricity can then be used again to power your car. According to HowStuffWorks, we can reduce our energy use with up to 45%. This means that less electricity has to be produced as well, since we use less. With the danger of our fuel running out soon (around 100 years), this regenerative braking becomes more and more important. Every bit of energy that we can save is positive.

I believe that we have to reduce our fuel consumption as much as possible, and this is a good way of doing so, but maybe there are more interesting, more promising options?


Aerodynamics – The fight against tornadoes.

Unfortunately the last decade the world is ravaged by several big natural disasters.

The Tsunami in Sri Lank and the earthquake in Haïti are regrettably the most well known.
If the increase of natural disasters is a result of global warming is still a great research topic. At the moment we aren’t capable of preventing them, because they are to rare and unpredictable. The only thing we can achieve at the moment is trying to understand the forming of them for faster warning of local people.

That is exactly what William Gallus, a meteorologist at Iowa State University tries to achieve, a “warn-on-forecast” principle. The very basics of a tornado are already clear to meterologists, but Gallus triest to find clues in storms to make tornado conditions more likely.

In Moore there were three very violent tornadoes in the last 15 years: one in 1999, one in 2003 and the last in 2013. Most of the scientist and meteorlogist say this is pure coincidence. Gallus believes that this cant be true due to the rarity of occurence of violent tornadoes. For this he started simulating, using tornado simulators, the effects of local topography on tornado-forming.

By analyzing this he tries to understand tornado forming in critical areas. Thereby they try to achieve to increase the warning time until the tornado will eventually strike. At the moment the average warning time is 13 minutes, but they want to reach 30 minutes at least. People will have more time to take shelter.

But here lies the following problem, most of the buildings aren’t designed to withstand the high stresses due to the incoming air. Some buildings can withstand 90mph straight-line winds, but a tornado is mostly fed by rotating air circulations of 90mph. Those shear stresses are mostly far too high for local buildings to resist. For this reason building design should be takin into account in regions which are statistical most vulnerable to tornadoes.

These are two domains were aerodynamics comes in hand to prevent the safety of the people.
Can you come up with another domain where science and technology tries to beat uncertain phenomena?


Reduce fuel consumption by avoiding the car

Another idea to reduce fuel consumption is by simply using your car less. We should not solely depend on technology to reduce our fuel consumption, but we should also try to implement other alternatives. These alternatives can be to use a bicycle in stead of a car to travel to your work or school. It can also mean that you try to make an agreement with your boss so that you can work from home. Technology has made it possible to work from home and still do the same work. You can use telecommunication to have meetings. You can also make use of the public transportation or carpool to reduce the fuel consumption. All these changes do not require your vehicle to be more fuel economic, but rely on common sense to reduce your fuel consumption. I found this consumer tip that gives 10 ideas to reduce your fuel costs (and thus your fuel consumption). However, there is only little attention for the alternatives of vehicle use.

I think that it would be more beneficial to use those alternatives than to reduce the fuel consumption of the car. If you can leave your car in your garage, you use no fuel and thus are helping the environment. In the article, I think more attention should go to the alternatives of using the car, in stead of increasing your efficiency. Although it is already a good idea to do so, the mindset should be shifted towards leaving your car at home.


Aerodynamics: reaching limits, but taking into account safety

As I already mentioned in some previous blogs aerodynamics play a large role in several sports, like cycling, the comments of Tim Steensel concerning the Red Bull Air race, but also Formula-1. Formula-1 is in my opinion by far the most technical sport where engineering plays a very important role. I won’t say the riders aren’t athletes, a F1- rider has to be in top shape when you take into account that they are dealing with forces five times greater then the force of gravity!

But the downside of the sport is the fact that the teams with the best engineering and scientific knowledge delivers the best racing machines. For this reason it is Merceds who leads the ranks for the moment. Their dominance is quite impressive.

In general the research and engineering domain of a F1-car can be dived in two main parts, the active parts like engine, suspension and so one. On the other hand there are the passive parts like the geometry and body of the race car. It is especially in this last domain where aerodynamics is crucial for developing a fast, great steering vehicle.

The main purpose of the aerodynamics is to reduce the drag force acting upon the F1-car. The drag force can be seen as the force which counteracts the motion due to the resistance of a fluid, in this case the incoming air. Designing the body with a very low drag coefficient is the goal they try to achieve. But only taking into account the drag led to strange results. The car encountered an upward force and started to actually lift from the ground and ‘fly’. This was a major problem concerning safety. Dealing with those speeds it is unthinkable that the car would eventually take off.

Therefore there is another important force which need to be taken into account, the lift force.
The lift force is the component of the force that is perpendicular onto the incoming fluid.
Most of the time the goal is to find an optimum to create the least drag as possible and enough downforce to establish stability and great steering performance of the vehicle.

For this they used the already well known research of the airplane wing.
In the application of an airplane the wing is designed to create a positive, upward lift force.
In contrary to the airplane the same design of the wing is used in F1-cars, but upside down to create enough downforce on the race car.

The thing I wanted to show you is the fact that with the aid of aerodynamics you can design more efficient and faster race cars. You can achieve certain limits. On the other hand aerodynamics also takes care of safety. My question is: Can you come up with some other technologies, domains were the technolgy led to an magnificent improvement and where it also was used in assuring the safety of the application.