[sustran] Re: Improving bus design cools passengers, saves fuel

[Gantasala Visweswara Rao]

I think this is innovative. The industry needs to adopt such GREEN
technologies to improve passenger comfort.

--Vissu

On Wed, Jul 22, 2009 at 6:00 AM, Jains <alok.priyanka at gmail.com> wrote:

> Interesting!! What happens when it rains or when it is too cold? The
> obvious option would be to close the vents but then the comfort of the
> passengers inside will get compromised.
> Regards
> Alok Jain
>   On Tue, Jul 21, 2009 at 3:13 PM, Eric Britton <eric.britton at ecoplan.org>wrote:
>
>>    I thought this was interesting. Any comments, further background?
>>
>>
>>
>> Eric Britton
>>
>>
>>
>> Contact: Sunil Kale
>> srk at mech.iitd.ac.in
>> Inderscience Publishers <http://www.inderscience.com/>
>> Slotted buses keep passengers cool Improving bus design cools passengers,
>> saves fuel
>>
>> A simple redesign of public buses used in hot and dry climates could make
>> passengers more comfortable without the need to use extra fuel running air
>> conditioning, according to a study published in the *International
>> Journal of Heavy Vehicle Systems*.
>>
>> Sunil Kale of the Department of Mechanical Engineering, at the Indian
>> Institute of Technology Delhi, India, and colleagues point out that the
>> majority of passenger trips are taken in open window buses.
>>
>> Worldwide, buses are the principal means of commuting within and between
>> cities, the researchers explain. For cost reasons, particularly in the
>> developing world, only a small fraction (less than 5%) of inter-city
>> vehicles are air-conditioned. They add that air-conditioning is not a
>> commercially or environmentally viable alternative to simply opening the
>> side windows and even the doors.
>>
>> Opened windows are supposed to improve airflow and keep passengers cool
>> while the bus moves. However, the cooling effect of open side windows is
>> inadequate for comfort in the hottest parts of the world on a crowded bus.
>>
>> Kale's team has now carried out an aerodynamic study of fluid flow in a
>> 1:25 model. Their findings suggest that a few simple modifications to
>> conventional design could significantly boost cooling airflow with none of
>> the cost or energy requirements of an air- conditioning system.
>>
>> The turbulent flow into a standard bus does not allow air into all areas.
>> Passengers sitting near or standing in the aisle do not receive any
>> ventilation, while those in the front seats receive airflow from the rear.
>> The team has found that a wide vent at the front and rear of a bus will draw
>> air into the bus at a much better rate than side windows. A similar boost
>> can be obtained with adjustable roof vents.
>>
>> These modifications would allow cooling air to increase the comfort zone
>> of the bus from a mere 11% of the interior volume to more than 50%. This
>> means that all passengers will experience some cooling airflow. In addition
>> to improved comfort there is an overall reduction in drag. Some of this drag
>> reduction could be sacrificed to provide grills and filters to prevent the
>> influx of insects and dust. Optionally a passive evaporative cooling system
>> could be incorporated into the vents to cool the incoming air and further
>> boost the comfort inside the bus.
>>
>> "In a long-term policy perspective of sustainable transport, buses form an
>> important mode of transport that needs to be strengthened," the researchers
>> say, "Besides improving fuel economy, passenger comfort is a major issue
>> with such buses especially in tropical climates."
>>
>> ###
>>
>> "Aerodynamics of a bus with open windows" in *International Journal of
>> Heavy Vehicle Systems*, 2009, 16, 459-488
>>
>>
>>
>>
>>
>>
>>
>> With all good wishes,
>>
>>
>>
>> Eric Britton
>>
>> Managing Editor
>>
>>
>>
>> | editor at worldstreets.org | World Streets <http://www.worldstreets.org/>| Paris  | +331 4326 1323 | Skype newmobility
>>
>>
>>
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>
>
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-- 
Vissu

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