Aerodynamic Bumper

[Smokeduv]

I think it's very good. Not my style, aesthetically speaking, but it works. The only thing I would worry about is about safety regulations, as in Europe they are very strict with things on the front bumper if I remember correctly, so, homologation for general sale could be a bit difficult.

[u.steinlechner]

One method, I used to measure the furel consumtion was a turbine flow meter.
Because a turbine does not measure exact changing flow rates, I measured at constant speeds.

The test track is a flat round course, driven at early sunday morning without influence of traffic. The weather conditions were equal. With GPS, I held constant speed. Average values came through multiple measurements.

Units are metric. km/h kilometers per hour. Consumption: liters per 100 km.

It is possible to change the aerodynamic parts within 15 minutes, so the time between the test is short.

Turbine Flow Meter


Counter
Hersteller (manufacturer) B.I.O-TECH e.K.
Typ ARS 260-A
ID 2160


Mini Durchflussmesser (flow meter)
Hersteller B.I.O-TECH e.K.
Typ FCH-m-PP-LC
Messprinzip Turbine
Düse 1mm
Impulszahl/Liter 10500

Treibstoff (fuel) Shell Super Benzin
Dichte (density) 0,7684
Temperatur °C 18

Flow Meter, GPS




Serial parts and aero-kit


Tools to mount the kit

[u.steinlechner]

Hello Smokeduv,

safety regulations in Europe are very stupid.

It is possible to modify the bumper to get the homologisation.
But it will cost about 15,000 Euro for each model.

The other thing is, that there are a lot of patents for pedestrian safety similar to my bumper. But the application of these patents does not fit in the homologisation.

A self-test showed, that is possible to run against the car without any injury or bruise. The shape of the bumper force a kinematic movement, if a pedestrian comes in front of the car. The pedestrian are forced to roll over the car.

[Oceanic815]

^^ I suspect some actual ankle or lower leg damage would result from a hit at speed, even if the rest caused a person to just roll off the vehicle.

Regarding pickups as you mentioned previously, as I would be interested to see what you have in mind for compact trucks as opposed to full size pickups.

[Smokeduv]

Originally Posted by u.steinlechner

Hello Smokeduv,

safety regulations in Europe are very stupid.

It is possible to modify the bumper to get the homologisation.
But it will cost about 15,000 Euro for each model.

The other thing is, that there are a lot of patents for pedestrian safety similar to my bumper. But the application of these patents does not fit in the homologisation.

A self-test showed, that is possible to run against the car without any injury or bruise. The shape of the bumper force a kinematic movement, if a pedestrian comes in front of the car. The pedestrian are forced to roll over the car.

That's what I was I thought. They are a bit stupid in some aspects and I was just stressing that it could be a pain in the ass to do the homologation (which, by what you're saying, it is :/ ). Anyway, it's good to see some innovation.

[u.steinlechner]

For trucks and tram the pedestrian saver must be modified.
Important is to deflect the pedestrian and to make sure not to overroll.

[freebeard]

Flow meter

Measuring flow rates at the small volumes vehicles use is apparently problematic. Have you looked at vortex street flow meter - Google Search

Pedestrian Safety

Similat to hitting deer. Better for both the impactor and impactee if the contact is below the center of mass. Add an optional hood-mounted air bag and you have a safety feature.

I see there's no changes to the understructure. So the air is divided between the wheelwells and radiator? Are you free to discuss the added speed holes?

[u.steinlechner]

Originally Posted by freebeard

Flow meter

Measuring flow rates at the small volumes vehicles use is apparently problematic. Have you looked at vortex street flow meter - Google Search

Pedestrian Safety

Similat to hitting deer. Better for both the impactor and impactee if the contact is below the center of mass. Add an optional hood-mounted air bag and you have a safety feature.

I see there's no changes to the understructure. So the air is divided between the wheelwells and radiator? Are you free to discuss the added speed holes?

Hi freebeard,

i like to make sure, that we are talking about the same thing.

I used a turbine flow meter to measure the fuel consumption at constant speed at driving.

The aerodynamic measurement were made in the FKFS aero acoustics wind tunnel.



Yes, I can talk about the airflow to the heat exchanger. The air intake is in front of the wheels and inside, the bumper is a expansion airbox. The speed of the air slows down and static pressure increases.

Greetings from Germany
Ulrich

[Vekke]

You did have two flow meters the second one on return line?

Conserning crash safety the law book is about 35-50mm thick. So there are lots of points your design does not meet. I would also estimate your leg bone will break at higher speed impact as force is distributed to smaller surface area. On that point its not safer pedestrian collision at least for adults.

However usually police or MOT inspection dont care if there are no sharp corners on the bumber. You can always sell them for offroad use to avoid that. I dont know any tuning bumber sold that is tested...

I had a similar design in my Seat and it worker perfectly at high speed driving. That is not the optimum shape but its only 1% worse than round nose and gives stability at higher speeds.

[aerohead]

*From the FKFS wind tunnel values,mpg might be predicted at 4-5.5%.
*If your car ran individually on the test track,on a calm morning,you might have experienced some laminar boundary layer conditions not present in the wind tunnel,skewing the aerodynamic drag downwards.
*In the United States,using the mass of fuel consumed would be considered a more accurate measure with respect to fuel consumption.
*If your 'Approach' angle is at least 16-degrees to the horizontal,then the bumper would have a chance to survive driveway ramps and such.(presently,some Volkswagen and Audi cars sold in the USA are losing some of their under-body components to ground strikes)
*The bumper is quite attractive and could evoke much emotional response in the market.