Slotted buses keep passengers cool

Jul 20, 2009

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 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 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."

More information: "Aerodynamics of a bus with open windows" in International Journal of Heavy Vehicle Systems, 2009, 16, 459-488

Source: Inderscience Publishers (news : web)

Explore further: Firm combines 3-D printing with ancient foundry method

add to favorites email to friend print save as pdf

Related Stories

Hybrid Bus in the City: A Prototype with a Future

Aug 20, 2007

Nuremberg’s public transport system has become more "electrified" thanks to a diesel-electric hybrid bus developed by MAN. The vehicle is equipped with drive-system technology from Siemens.

Defectors take the car, cooperators go by bus

Feb 03, 2009

National economies are driven by the automobile, even during an economic downturn. Every day, hundreds of millions of people take their cars to visit remote places, to commute, and to reach the supermarket.

A train on the street

Dec 15, 2006

Streetcar or bus? The AutoTram® offers the best of both: Up to 36 meters long, it can carry as many passengers as a streetcar while being as versatile as a bus. A flywheel energy storage system absorbs part ...

Lawsuit claims school bus pollution

May 03, 2006

Two environmental groups filed a lawsuit this week in San Francisco, claiming some school buses fill with cancer-causing levels of diesel exhaust fumes.

Recommended for you

Firm combines 3-D printing with ancient foundry method

21 hours ago

A century-old firm that's done custom metal work for some of the nation's most prestigious buildings has combined 3-D printing and an ancient foundry process for a project at the National Archives Building in Washington, ...

Wearable device helps vision-impaired avoid collision

Mar 26, 2015

People who have lost some of their peripheral vision, such as those with retinitis pigmentosa, glaucoma, or brain injury that causes half visual field loss, often face mobility challenges and increased likelihood ...

Applications of optical fibre for sensors

Mar 26, 2015

Mikel Bravo-Acha's PhD thesis has focused on the applications of optical fibre as a sensor. In the course of his research, conducted at the NUP/UPNA-Public University of Navarre, he monitored a sensor fitted to optical fibre ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.