The team modified the engine of Semar Proto from multispeed gearbox to single speed gearbox with one-way sprocket, which allows the vehicle gliding or sliding well, "added Alfian.
The Semar Proto’s mentor Dr. Jayan Sentanuhady who has been coaching the UGM teams for SEM Asia 2010-2011 and assist the students in both events explained that the Semar Proto team has conducted various experiments to maximize vehicle performance in SEM Asia 2011. "The engine of Semar Proto has low friction and heat-loss. We reduce the vehicle’s weight by removing unnecessary parts such as oil pump and transmission. The engine’s compression ratio was also increased from 8 to 11.5 to improve the thermal efficiency of the engine. It also fits with the character of Shell gasoline octane 95," explained Jayan, Mechanical Engineering lecturer of UGM who obtained his PhD from Saitama university, Japan.
The Programmable Injection System
To reduce fuel consumption, Semar Proto also uses the fuel-injection system which can be programmed so that the fuel metering is more precise and fit to the needs of the engine. Meanwhile the body of Semar Proto was optimized with computational fluid dynamics simulations using fluent software.
"To reduce the turning radius of vehicles, we change the original concept of the wheel position from the previous position in the cabin to the outside of the cabin. We also lowered the center of gravity of the vehicle to stabilize the vehicle when cornering," said Jayan. Learning from experience in SEM Asia 2010, the UGM mechanical engineering students have tried to do innovative breakthrough and creative techniques.
In the SEM 2011, UGM sent two types of vehicles ; prototype (Semar Proto) and urban (Semar Urban). Prototype vehicle has minimum three wheels, focusing on innovative and aerodynamic design to reduce wind resistance and minimize energy use. The Urban type is four-wheeled vehicle that looks similar to the existing urban vehicles on the road today.
With improvements in design, material selection and engine, Semar Proto vehicle has finally been able to run on tracks in the Sepang International Circuit and achieved 137 kilometers in one liter of gasoline, while Semar Urban reached 71 km in one liter of gasoline.
"Our Semar vehicles’ body are actually streamlined, but they are still too heavy. We have to learn a lot to catch teams of Thailand and China for the SEM Asia next year, "said Jayan briefly.
The SEM Asia 2011 held in Sepang, Kuala Lumpur, Malaysia on July 6 to 9 and followed by 94 teams from 12 countries in Asia. This competition challenged student teams to design and build energy-efficient vehicles that can travel the farthest distance using minimum of fuel. Ten teams from Indonesia who participated in the SEM Asia 2011 are ITS with Sapu Angin 3, Sapu Angin 4 and Sapu Angin 5; ITB with Cikal and Rakata, UI with Garuda Kevasha and Kalabia; UGM with Semar Proto and Semar Urban; and Politeknik Negeri Pontianak (POLNEP) with its Equator Line vehicle.
In addition to on-track fight Awards (awards for the race cars on the circuit teririt), SEM Asia also provides award-Off-track (outside the circuit) the Technical Innovation Award (Technical Innovation), Safety Award (Safety), Best Design Award (design best), Communications Award (Communications) and People's Choice Award (Vehicles Go to selected on-line).
Sapu Angin 4 ITS which recorded the mileage of 150 km per liter using biodiesel fuel (fatty acid methyl ester / FAME) got the Grand Prize (the major champion) in the Internal Combustion class and won the Alternative Diesel Award. Cikal ITB received the Grand Prize in Urban Gasoline category and the Silver Award for Urban Internal Combustion. In addition to succeeding in the Urban class, the Indonesia teams also received two awards in the off-track category; the Semar Proto of UGM as the best in the Technical Innovation, while Rakata team of ITB won the Communications Award.
For further info on Shell Eco-marathon, please visit www.shell.com/ecomarathon
Sri Wahyu Endah
Media Relations Manager
PT Shell Indonesia
Tel. +62 21 75924700
Fax. +62 21 7594688