Download - Pitstop june 2014

Year at a glanceFS 2014 edition

Contents01 ..........Research at IITB

03 .......... Improvements in EVo 3.0

06 .......... Design Launch Report

07 .......... Our Sponsors

08 .......... The IITB Racing Family

05 .......... Sponsors’ Feedback

Contents

FS 2014 edition

Racing Up the Ladder

ResearchAT

Aerodynamics

IITBRacing

number of performance and safety related aspects of motor sports have received attention in recent years. With the advent of

electric race cars in Formula Student, safety has become even more important. Two critical areas that we identified were aerodynamics for perfor-mance improvement and accumulator system for safety aspects. Because of the limited timeframe we have for the competition and given the com-plexities involved in these aspects of race car design, we have put them into research category. We have involved faculties and masters student to guide and help us in these research projects with the long term objective of implementing the results in future cars of the team.

A

The use of aerodynamic devices is quickly becom-ing a necessity in Formula Student. So in order to understand its effectiveness, we started working on aerodynamics. For this season the objective of aerodynamics subsystem was drag reduction by streamlining the bodyworks, thereby improving the fuel economy. With no prior knowledge and experience in aerodynamics and CFD, our initial focus was on development of technical expertise in this field.

Various design iterations were done with increas-ing level of complexities to ultimately perform full car CFD. A substantial reduction in drag force of 18.8% is achieved which can be attributed to lower frontal area and streamlined bodyworks design. Energy consumption of the vehicle for endurance race is reduced by 11.5 % improving the fuel econ-omy.

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Thermal aspects of accumulator

Using the CFD expertise that we gained, design and development of complete aero package has been started. Wind tunnel validation of drag study will be done in aerospace engineering department on scaled down models. Complete aero package will also be validated by wind tunnel testing.

The development of safe, high voltage batteries is regarded as a major challenge in electric car design. The safety issue concerns the thermal aspects of battery pack. A Li-ion cell generates heat during both charge and discharge, and the heat generation in the battery can increase sharply leading to temperature rise above safety limit. It also affects the performance and life of the cells. In this research project we focused on the thermal characteristics of battery pack i.e. the temperature profile across the pack as the car runs during endurance.

Other thermal properties like specific heat capacity of the pack and conductivities were evaluated by experiments. For this season it was ensured that the temperature does not rise above the safety limit. Other data collected and estimated will help the future teams in designing the cooling system for the battery pack if required. More advanced thermal models and experiments to validate them are being developed by the team.

Two papers on these projects titled as “Parametric study of drag force on formula student electric race car using CFD” and “Thermal characterization of lithium polymer battery module for electric vehicle application” were submitted to 2nd International Conference on Me-chanical, Automotive and Materials Engineering (CMAME 2014). Both of them have been accepted for presentation during the conference.

PITSTOP- June 2014 1

Banking | Capital Markets | Insurance

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UNCOMPLICATEWhat causes uncertainty in insurance companies today? Is it increased product proliferation, demand for more

sometimes— invisible risks?

At Tata Consultancy Services, we believe that the need of the hour is to ‘Uncomplicate’.

The need of the hour is to put in place a solution that can manage all sources of complexity and enable products to deliver the same transformational impact, but at substantially lower costs. TCS BaNCS seamlessly integrates front-, mid- and

A product suite that encompasses a range of line of businesses, our insurance platform ensures quick time-to-market while it capitalizes on changing customer needs and channel preferences. In fact, this solution transformed a large insurance group in UK with six business lines, 1,100 products, 13 platforms, 7 million policies and 6 million customers to a single instance of TCS BaNCS, thereby delivering enhanced performance.

Now, don’t you think it is time to uncomplicate?

ImprovementsInEv 3.0

Chassis and bodyworks

Overall Improvements• Weight Reduction:

• Tunability: Wireless tuning of e-differential parameters helps us achieve better tunability.• Reliability: Reliability has been given key focus during design, fabri-cation, validation and testing

• Weight and overall height reduction: The weight of chassis was reduced by 16% majorly by narrowing the cockpit and reducing the roll hoop height. The reduction of height was achieved by tilting the driver seat angle to 40 degree without compromise of driver vision• Custom Impact Attenuator: Custom IA was designed, fabricated for the first time using Rohacell high density foam and tested at the Auto-motive Research Association of India

SubsystemChassis and BodyworksVehicle DynamicsPowerdrainElectronicsBatteryOverall

o

Chassis and bodyworks

Overall Improvements• Weight Reduction:

• Tunability: Wireless tuning of e-differential parameters helps us achieve better tunability.• Reliability: Reliability has been given key focus during design, fabri-cation, validation and testing

• Weight and overall height reduction: The weight of chassis was reduced by 16% majorly by narrowing the cockpit and reducing the roll hoop height. The reduction of height was achieved by tilting the driver seat angle to 40 degree without compromise of driver vision• Custom Impact Attenuator: Custom IA was designed, fabricated for the first time using Rohacell high density foam and tested at the Auto-motive Research Association of India

• Aerodynamics: For the first time, an aerodynamics subsystem was established to focus on streamlining of bodyworks for better fuel economy. By doing CFD simulations and iterative bodyworks design significant reduction of 18.8% is achieved in drag force acting on the car.

Powertrain

• E-Differential: EVo 2.0 e-differential implemented a slip control strategy wusing wheel RPM feedback. EVo 3.0 implements torque vectoring using yaw rate control helping us achieve better driver comfort and improved handling by avoiding over or under steer.

Evo 2.067 kg95 kg73 kg12 kg90 kg340 kg

Evo 3.062 kg64 kg58 kg11 kg55 kg250 kg


Battery and safety

ImprovementsInEv 3.0

• Drivetrain: EVo 3.0 houses an innovative planetary gearbox weigh-ing merely 9 kg, in comparison to EVo 2.0’s two-step gearbox weigh-ing 16 kg.

Improvements

Integration

Robust safety system

Easy Debugging of safety system

Battery casing

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Electronics and harness

Battery and safety

Vehicle Dynamics

• Drivetrain: EVo 3.0 houses an innovative planetary gearbox weigh-ing merely 9 kg, in comparison to EVo 2.0’s two-step gearbox weigh-ing 16 kg.

• Custom Vehicle Dynamics model: A MATLAB model was developed that incorporated tire data, roll calculations and steering geometry, helping us simultaneously design a suspension and steer-ing system that maximized the overall vehicle performance.• Weight Reduction:

• Wire Harness: This year’s motto is to keep wires less intercon-nected to each other and use separate connectors for bunch of differ-ent types of signals. For ease in connections between PCBs and con-nectors, PCB mounted connectors are used. Also for more reliability and compactness, we are keeping all the PCBs in just one enclosure• Data Acquisition: This year our objective is to make the DAQ system wireless to avoid plugging the USB cable for exchange of data. Our DAQ system processes and logs all the data onto a fast and pow-erful central computer, BeagleBone Black, not missing a single bit of crucial data and sending this data for laptop to observe. The data from sensors will be sent to laptop using the long range XBee module while the Car is running so that it can be analysed in real time.

Suspension and wheel AssemblyRocker, Spring, ARBSteering AssemblyBrake AssemblyOverall

67.85 kg6.76 kg4.43 kg19.93 kg98.97 kg

44.09 kg3.80 kg2.62 kg13.65 kg64.16 kg

Evo 2.0All the components inside battery were mainly integrated using cables and con-nectors

Filters were introduced later which result-ed in bad integration of the boards

LEDs were incorporated for identification of faults. Internal signals needed to be debugged using a multimeterAluminium battery box weighing 3.5kg

Improvements

Integration

Robust safety system

Easy Debugging of safety system

Battery casing

Evo 3.0The electronic components are mainly placed on the printed circuit board which interconnects them.

The board was designed to be noise tolerant by adding filters and appropriate pull up/pull down resistorA micro-controller monitors important signals on board. On failure it communi-cates with DASH and displays the failure.Carbon fibre box weighing only 1.5kg


Sponsors’Feedback

DesignLaunch

Report

This year, IIT Bombay Racing decided to have separate launch for the design prior to the car launch. The Design Launch of Evo3.0 was held during the third day of the Techfest 2014, technical festival of IIT Bombay. Designs from both, mechanical and electrical subsystems were revealed during the event, which was attended by Prof. Urjit Yagnik, Dean (Student Affairs) of the institute and officials from sponsors com-panies like NRB Bearing, Imaginarium and Mathworks* . Members of other college’s racing team were also present.

The launch event was hosted by the team captain, Siddhesh Sakhalkar. During the launch, heads of each subsystems presented their designs. Imaginarium gifted a small-scaled version of the Evo3.0 manufactured through 3D printing, which boosted the team’s enthusiasm. After the presentation, 2nd edition of PITSTOP “Design Launch Edition” was launched. The event ended by a concluding speech from Akshay Goyal (Head, Organisation Team) thanking all the students, Dean(SA) and dig-nitaries from the sponsor companies.

Besides the Design Launch event, IIT Bombay Racing also showcased the last year’s car Evo2.0 during the 3-days exhibitions at Techfest 2014. At the exhibitions, posters of each subsystem’s design for Evo3.0 were displayed.


OurSponsors

Automotive, Marine and Speciality Coatings

Automotive, Marine and Speciality Coatings


theIITBRacing

Family

Lookback:

Siddhesh SakhalkarTeam Leader and Chief Mechanical Officer+91 9869 209 [email protected]

Puneet AroraChief Electrical Officer+91 9819 765 [email protected]

Akshay GoyalChief Operations Officer+91 9930 842 [email protected]

Download - Pitstop june 2014

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