Assignment 1

ASSIGNMENT 1

Q1.

GT SUITE is a vehicle design and analysis software. The current licensing option that we are using contains 14 Modules/Applications

as shown in the image below. This can be traced by opeing a GT Project map via - File>Model [Under Create New]>GT Project Map(.gtm)>GT Suite.

Underneath the image is brief description of these various modules.

1. AC/Waste Heat Recovery: This feature is used to simulate Air Conditioning Unit and understanding the thermal impact on the various components ranging from the coolant fluid to the piping system, cabin conditions etc. Comprehensive thermodynamic study of this system is possible by manipulating component geometry, material, masses etc. to yeild best results. Then optimizing the individual components [Pump, Condensor, Evaporator, Expander] to match their operating points.

2. Exhaust Aftertreatment: We all are living in a society which is focusing on Enviornmental friendly emission standards more than ever, so, there is a widespread demand of cleaner emissions from IC engines. Due to chemical kinetics of Combustion process we get various harmful gasses and thus the need of Exhaust Gases treatment mostly via Catalytic Convertors [CatCon]. This model helps user to develop a Selective Catalytic Reduction [SCR] System and its optimization, tracing the content of species of compounds produced during combustion. For CI engines it has a feature to filter out particulate called Diesel Particulate Filter [DPF] to counter the issues of soot particles. Eventually it makes us integrate the engine and exhaust/aftertreatment models.

3. Cabin: This system even provides sophesticated feature of incorporating the windscreen properties to simulate conditions when a vehicle is in sunlight to correctly quantify the cabin conditions in TAITherm. Setting up of mesh grids, in COOL3D, Boundary conditions in GT-ISE and later on optimising the solution. CFD flow mappiing could also be done on this.

4. Controls: This feature helps user incorporate the benefits of Control Theory in the simulation. PID controller is used to interact with the plant. Controller can be build using this provision to control boost pressure for wastegate actuation in turbocharged setup. It helps keep the setup running in limits of mechanical properties.

5. Cooling Engine: This feature works on integrating certain test and physical parameters of an engine and using them to enable making of a simulation by incorporating components like: Geometry, CFD Calibration data, Engine & Friction model for the parts, water jacket provision, creating cylinder portion and defining details for it, valve and port allocation, applying various thermodynamic connection which govern the heat transfer, integration of the model into an FRM, integration with other assemblies of a vehicle like coolant system, oil system and under-hood system. Even possibility of running an FEM model of the engine is provided in this feature for comprehensive study if the engine block’s thermal behavior.

6. Cooling System & Thermal Management: As we know that IC engines have a thermal efficiency in the range [25%-45%] depending upon the nature of engine. This essentially means that all IC engines reject huge amount of heat during working. Hence, there is a need to reject this heat away from the mechanical components in order to ensure that engine seizure does not occue. This module provides the option to design and analyse engine thermal management systems that can handle wide range of heat management issues. It uses one-dimensional fluid dynamics, representing the flow and heat transfer in the piping and in the other components of a cooling system. Several parallel fluid circuits can be modeled simultaneously, each containing a different fluid. it provides the flexibility needed to model advanced concepts, and it also includes a built-in vehicle/engine simulation for calculation of thermal loads under any driving cycle.

7. Cranktrain: It is used to design a simulation environment for a cranktrain like single line multi cylinder crank train, balancing of the crank train, double throw V-8 crank train, study of mechanical properties like bending & stress analysis during running state. Establishing the crank-slider mechanism, using 2D mechanics library. Also , we can use the GEM3D to build a crank train model using CAD.

8. Engine Performance & Acoustics: This feature gives user the ability to simulate engines of various configurations ranging from relatively simple single cylinder engines to complex multi-cylinder turbocharged engines eventually cutting down the investment of both time and money as in conventional engine development process which was done by making prototypes of engines and then modifying the parts as per actual physical testing/runningof the engine. This module introduces the basic objects like Environment, Runner, Ports, Valves [ for both intake and exhaust side independently], Cylinder, Injector, Crank Train etc. How to introduce these into a project map, link building between parts and then the Run feature enables user to run the simulations.This module has much more flexibility like options on basis of combustion namely; SI or CI engine. Turbocharging an engine and its tuning is also possible using this module. Another feature of this module is provision of Acoustic Study of the exhaust gases. Muffler design can be optimized using this by understanding the trend of thermal to sound energy conversions and later on its optimization. Option of Fast Running Model [FRM] Generation is also available in this module and more sophesticated scope of this application extend up to building of a model that takes inputs from the most suitable case from a DOE study and then using those parameters to train a Neural Network in order to produce a model to emulate an engine that virtually presents near to real life scenario like output results.

9. Fuel injection [FI] & Hydraulics: The fuel injection part of an engine is one of the most important parameter when tuning either for engine performance/economy. This feature helps user to simulate Fuel Injectors stating from Simple Common Rail Injector inputting flow components and their linkings to identify the flow. The second important part of any FI system is it\'s control valves and mechanical actuators. This module enables us to incorporate these Hydro-Mechanical valves. Various Fluid-Mechanical Templates [FMTs] are also provided to be integrated with engine for optimum tuning.

10. Gear Chain Belt Drives: Designing of Belt with relevant mechanical properties, setting up the gear drive and its timing is done in this feature. This helps us create the objects, parts and links amongst them. Two chain timing belt can also be simulated using this feature.

11. Lubrication: This feature tells us how to build a 1 Cylinder Lubrication Model. Let’s us create a Mean Value Bearing, Custom Oil Fluid Properties can be changed. We can modify a Lubrication System to Analyze Priming. Building a Detailed Vane Pump Model from CAD is another aspect of this feature.

12. Transmission: One uses a transmission system in a vehicle to transmit power from source to wheels. As per driving conditions the load is send via various gear train mechanism involving clutch, gearbox, couplers etc. This features enables one simulates both automatic and manual transmission setups. Setting various objects like planetary gears, Input/Output shafts, speed boundaries, clutch type etc. Even advanced clutches like DCT can be modeled in this feature.

13. Valvetrain: This feature lets us develop comprehensive valve train system of an IC engine. It has the facility to create very basic components of a valve train like Valve springs, lifter-pushrods, Rocker arms, integrating them all to build an SOHC, introduce cam profile, plotting the simulations, designing new hybrid cams, studying cam model boundary conditions while working and its optimization. Study of valve train sensitivity is another feature provided in this module.

14. Vehicle Driveline & HEV:Introduction of a Battery Electric Vehicle BEV could be done using this feature. Conventional methods of the Hybrid Electric Vehicle [HEV] are given in this module. Integration of Engine & Motor in the driveline is possible; transmission line is covered in this feature [both manual & automatic].

Q2.

- Time Control Flag can be traced by opening a map file then in title bar choose Run Setup [Under Model Setup]>TimeControl Tab>Time Contol Flag.

- Time step and solution control can be traced under Run Setup [Under Model Setup]>FlowContol>Time Step and Solution Control.

- Integrator/Solver type can be located under Run Setup [Under Model Setup]>ODEControl>Integrator/Solver Type.

Q3

Run Setup:

It has following settings:

• TimeControl: Defines the global simulation type with regard to time, currently it has a Max Simulation Duration of 5sec & Min simulation duration is set on ignored. Auto shut-off is on & Main driver which defines periodic frequency is on Automatic mode.
• Initialization: Part Attributes is selected, which will initialize the simulation with the attributes specified in the parts on the model map for every case
• FlowControl: Part name list object is set to default, Time step & Solution control object is Explicit.
• ODEControl:
  • Part Name List Object Identifying Circuits Belonging to Column: def
  • Matrix Sparse Format Solver (BETA for CSR): skyline
  • Matrix (Node Order) Optimization Method: Cuthill-Mckee
  • Integrator/Solver Type: Explicit – Runge -Kutta
  • Time Step and Solution Control Object: Explicit-def
  • Time Step Output Frequency: def
  • Solve All Circuits Together (Single Solution Cluster for the Column): ODE Setting #1
  • Displacement SS Tolerance for Auto Shut-Off: ign
  • Velocity Steady-State Tolerance for Auto Shut-Off: ign
  • Torque Imbalance Tolerance for Auto Shut-Off: def = 0.002
  • Consecutive Cycles/RLT Update Intervals for Steady-State: 1
  • Modal Analysis Property Object: ign
  • Matrix Inversion Scheme (electrical sol. only): SVD

• SignalControl: Nothing is selected

• ThermalCOntrol:
  • Thermal Wall Calculation Interval: def
  • Thermal Wall Steady-State Tolerance for Auto Shut-off: ign
  • Convergence Threshold for Flow Solver Skipping: ign
  • Number of Thermal Calculation Intervals to Skip Flow Solver: ign
  • Periods at Initial Wall Temperature (WallTempSolver only): def = 3

• ConvergenceRLT: Nothing is selected

Advanced Setup:

It has following settings:

1. 2. 3.

4. 5. 6.

7.

Plot setup

It has following settings:

Output Setup

It has following settings:

1. 2.

3. 4.

5. 6.

7. 8.

Q4

The Attachment contains the GTmap, GTpost and .dat files.

The simulation ran succesfully and converged @ time =0.25 sec.

The total heat transfer at Charge Air Cooler as per simulation came to be 8.73 kW

The Pressure Drop across Charge air cooler came out to be 0.0837 bar