Assignment 1

INTRODUCTION

GT-suite offers engineering operation ranging from fast concept design to detailed system or sub-system/component analyses, design optimization, and root cause investigation. It is a multi-purpose platform with many physical libraries, containing both fundamental and higher-level components. Using these components, engineers are empowered to build system models of almost unlimited variety.

MODULES LISTED

GT-suite is an ideal choice for full vehicle design and analysis. The applications for this package includes:

(i) Engine Performance and Acoustics: The engine performance and acoustics library is designed for steady-state and transient simulations and can be used for analyses of engine and powertrain control. It is applicable to all types of internal combustion engines and provides the user with many components to model almost any advanced concept

(ii) Cooling Systems and Thermal Management: GT-SUITE is an advanced code for design and analysis of engine thermal management systems that has been specifically designed to handle this wide range of heat management issues and disciplines and can be used to integrate all of the activities related to heat management to meet design objectives such as engine durability, emissions, fast warm-up, passenger cabin heating, component sizing and specification, and system control.

(iii) Air Conditioning/Waste heat recovery: Two phase refrigerants are used as the working fluid for a wide range of applications. Many such applications are used in modern vehicle design in order to ensure passenger comfort (Air Conditioning or Heat Pump) or harnessing the power present in the high temperature exhaust gas from the engine (Waste Heat Recovery Rankine Cycle). GT-SUITE is a multi-disciplinary tool that can aid in the development of such systems by accurately predicting the behavior of such system in different stages of design.

(iv) Fuel injection: It is capable of modeling the coupled behavior of hydraulic and mechanical components. In the context of fuel systems, it is applicable to any diesel or gasoline system, including both common rail and unit pump systems. Alternative fuels can also be handled. GT-SUITE has been designed to study steady-state and transient system response.

(v) Lubrication Circuits: GT-SUITE is a great tool for modeling engine lubrication systems, using a compressible 1-D CFD solution that solves for mass, momentum, energy and species. The primary purpose of modeling a lubrication system is to predict flow rate and pressure distribution throughout the system. Its applications include steady-state flow and pressure distribution in an oil system, pump sizing and priming etc.

(vi) Vehicle and HEV Fuel economy & Performance: The GT-SUITE Vehicle Library provides users with a set of standard driveline components and connections that can be used to construct various driveline layouts and configurations.

(vii) Transmission and shift quality: It contains automatic transmission power flow, vehicle integration, hydraulics and controls.

(viii) Cranktrain and Crankshaft dynamics: One of the two main sources of forces, moments and torques which affect the dynamics of an IC engine is the cranktrain, or the moving parts which transmit torque and power for external use. The cranktrain is made up of the crankshaft, connecting rods and pistons. Part of the crankshaft design, specifically the angular positions of throws, or crankpins, is very much a function of engine configuration, i.e. whether the engine is 4- or 2-stroke, inline or V-type, and the number of cylinders and in GT-suite we don’t need to specify it explicitly.

Other modules include:

(ix) Exhaust Aftertreatment.

(x) Hydraulics and Pneumatics.

(xi) Valvetrain Kinematics and dynamics.

(xii) Timing and Front end drive systems.

(xiii) Engine Real-time.

(xiv) Aerospace Systems.

Time control flag: Time Control Flag option can be found under Run Setup option in Time Control tab. Continuous indicates that the simulation includes no periodic event, and therefore has no need to track results with respect to a cyclic angle. This is the typical setting for models that contain only quasi-steady fluid circuits such as coolant or underhood air. The simulation duration for a continuous simulation is typically specified in time.

Time step and solution control:

Integrator/Solver type: Explicit Runge-Kutta integration scheme that is 5 th order accurate. This integrator is recommended for non-stiff problems.

INTERCOOLER :-

A device which is used in turbo-charged and supercharged (forced induction) I. C. Engines (internal combustion engines) to improve their volumetric efficiency by increasing intake air-charge density through isochoric cooling is called as charge air cooler/ intercooler.

The main physical part of the intercooler will consist of a multiple pipe object. For multiple pipe objects, the user enters the geometric data for a single pipe and then enters the number of pipes required. Here cooler-in-1 and cooler-in-2 are inlet and outlet pipes for CAC.

A 'FlowSplitGeneral' object to connect the intercooler inlet pipe to a bundle of pipes that will represent the heat exchanger core. In GT-POWER, a flow-split must be used to connect a single pipe to multiple pipes for pressure drop.

The inlet and outlet conditions are :-

• Inlet mass flow rate = 1200 kg/ h at 100 degC
• Outlet pressure 2 bar at 30 deg

• Diameter of cooler inlet and outlet pipe= 50 mm
• Length of the CAC= 1000 mm

RUN SETUP SETTINGS :-

Advanced setup :-

Plot setup:

Output Setup:

RESULTS:

For the above given input values

1. Total heat transfer at Charge air cooler (CAC) is calculated through the formula `Q = mC_pΔT` which equals 4.37 kW

where:
Q – Heat Rejection (kW)
m – Mass flow rate (kg/s) = (1200/3600)
Cp – Specific heat capacity (kJ/kg-K) = 1.01
∆T – Temperature difference (K) = 363-350 = 13

Q= (1200/3600) x 1.01 x 13 = 4.37 kJ/s = 4.37 kW

2. Pressure drop across CAC was observed as 0.0836bar