Aerodynamics Study of Co2 Car Design

Aerodynamics Study of Co2 Car Design

Anjappa SB1, Satish Shegedar2, G Naveen Raju3, Vinay Thallapally4.

Asst Professor Mechanical Engineering Department

Sree Chaitanya College of engineering, Karimnagar Telangana India.

Abstract when objects pass through air, forces are produced by virtual motion between the air and surfaces of the object. Aerodynamics is the education of these forces, generated by means of the motion of air, commonly aerodynamics are taken into consideration rendering to the kind of flow as subsonic, hypersonic, supersonic and so forth. This take a look at is accomplished at the scaled model of the dragster race car, because the dragster wishes extra space & substantial value to construct and test the identical, to reduce the cost and speedup the refinement manner, we have carried out this study on the miniature model of the car and tested with the wind loading of 57MPH to analyse the wind loading and the obstruction in the path of movement.

The initial study is performed at the primary geometry of the car to test the drift parameters. The second take a look at is finished on the subtle model of the car, ensuring all of the uncovered corners are rounded to avoid obstruction of air and make certain clean waft of the air. Drag and lift parameter is basically reduced in this look at because of the change inside the body layout and addition of curves and drafts on the flow surface of the Co2 car surface.

Key Points: Race Car, Dragster, Co2, Solid Works.

1. INTRODUCTION

   An essential thought in outlining a car is aeromechanics. The study of air is the effect of wind current and the powers included whilst an article travels thru the air or when air moves past an object. Flight technological know-how has tackled new importance since the requirement for more fuel- productive vehicles. An inadequately composed vehicle makes use of greater fuel. The flow of air shifting round a car is called streamline. A body with a preferred adjusted or rectangular form will bring about air to split a ways from the streamline into whirls of air. This uneven or turbulent air improvement with the intention to ease the vehicle off is known as drag. Vehicles have much less resistance on the off hazard that they are adjusted inside the front and reduced to a degree in the again (teardrop shape). In this motion, you will define, develop, and check an aero robotically stable car. The auto you'll be building is similar to a smaller than expected rocket fuelled hot rod. As you manufacture your warm rod, take as a whole lot time as required. Its going to have an advanced opportunity of looking exceptional and going quick at the off hazard that you assemble it with tolerance and consideration. One noteworthy slip-up can spoil the entire hot rod and forestall you from dashing Take pleasure on your work and attempt to make the fine dragster inside the elegance.

   In this section a few fundamental air motion optimized requirements and their applications to aircraft aeromechanics will be mentioned. During the talks in this element the wind circulation might be considered as unfaltering. This means that all flow properties, as an example, weight, speed, temperature and thickness are concept to be free of tome. But in a little district near to the plane surface, in which consistency is imperative, the wind current will likewise be notion to be non- gooey or in viscid.

2. PROBLEM DEFINATION AND SCOPE OF PRESENT

   WORK.

   1. Objectives

      Analysis will be carried out using solid works software to predict air flow parameters and drag on the component by considering external flow simulation at 57MPH.

   2. Methodology

      • From the literature background the gap in a paper is to design and study of aerodynamics co2 car. This will be considered has the objective of this work.

      • Solid works software is used for modelling, meshing and analysis of the car.

      • Applying material properties and boundary

        conditions on a element, as per ASTM standards.

      • Analyzing the airflow of car and predicting two parameters, drag and lift.

      • Finally predicting reduction in drag component, under different surfaces.

      • Correlating both results.

   3. Scope

Our scope of the project is to study the aerodynamic flow of the air and the drag forces during the travel of the car at high speeds.

Considerations for the study.

1. Speed @ 57MPh

2. Car body is designed to have curvatures and angled surfaces to the direction of travel.

3. Gravity and wind force at normal atmosphere is considered.

4. Self-weight of the car is also considered.

5. The flow characteristic results show the aerodynamic parameters and the drag if any in this study.

   1. RESULTS AND DISSUASIONS

      Fig: 3.1 basic model of co2 car

      • Model information – Optimised design

      • Current configuration 57mph

      The initial design was having sharp edge faces and faces intersecting into corners, which are aiding the direct obstruction of the air flow during motion.

      Model	Co2 car assy-old SLDASM
      Project path	F:\SCCE2016\CO2carproject
      Unit system	SI (m-kg-s)
      Analysis type	External
      Coordinate system	Global Coordinate system
      Reference axis	Z

   2. MESHING GEOMETRY

      Fig: 4 meshing geometry of ccar model

      2D Plane flow	None
      At X min	Symmetry
      At X max	Default
      At Y min	Default
      At Y max	Default
      At Z min	Default
      At Z max	Default

      2D Plane flow	None
      At X min	Symmetry
      At X max	Default
      At Y min	Default
      At Y max	Default
      At Z min	Default
      At Z max	Default

      1. BOUNDARY CONDITIONS

         1. Ambient condition

            Thermodynamic parameters	Static pressure : 101325pa Temperature 293.26 K
            Velocity parameters	Velocity vector Velocity in X direction : 0 mile\h Velocity in Y direction : 0 mile\h Velocity in Z direction : – 55.0000000 mile\h
            Turbulence parameters	Turbulence intensity and length Intensity : 0.10% Length : 8.337e-004m

      2. Input Data

         1. Initial mesh setting

            • Automatic initial mesh :on

            • Result resolution level : 4

            • Advanced narrow channel refinement : off

            • Refinement in solid region : off

         2. Geometry resolution

            • Evaluation of minimum gap size : automatic

            • Evaluation of minimum wall thickness : automatic

      3. Computational domain

         X min	p>0
         X max	0.274 m
         Y min	-0.228m
         Y max	0.304m
         Z min	0.546m
         Z max	0.381m

      4. Calculation control options Finish conditions

         Finish conditions	If one is satisfied
         Maximum travels	4
         Goals convergence	Analysis interval : 5e-001

      5. RESULTS

         1. General info

            • Iteration: 138

            • CPU time: 221s

         2. Calculation mesh

            • Basic mesh dimensions-old

      Number of cells in X	19
      Number of cells in Y	40
      Number of cells in Z	74

      1. Number of cells

         Total cells	57227
         Fluid cells	56109
         Solid cells	309
         Partial cells	809
         Irregular cells	0
         Trimmed cells	0

      2. Maximum refinement level: 1

      4.7.1 Goals

      Name	Value	Progress	Use in convergence	Delta	criteria
      Drag	-32.824	100	On	0.14747	3.6120
      Lift	12.043	100	On	0.208961	0.2255

      1. Min /Max Table

         Name	Minimum	Maximum
         Pressure [pa]	100955.23	101967.23
         Temperature [K]	293.07	293.85
         Density (fluid) [kg/m3)	1.20	1.21
         Velocity [mile/h]	0	65.5408196
         Velocity X [mile/h]	-15.7155005	19.6210812
         Velocity Y [mile/h]	-31.6410901	34.9538794
         Velocity Z [mile/h]	-65.4000224	6.0181535
         Temperature (fluid ) [K]	293.07	293.85
         Mach number	0	0.09
         Vortices [1/s]	0.044	14555.541
         Shear stress [pa]	0	4.24
         Relative pressure	-369.77	642.23
         Heat transfer coefficient [w/m2/K]	0	0

      2. Engineering Database

         Gases Air

         Path: gases pre-defined

         Specific heat ratio (cp/cy): 1.399 Molecular mass: 0.0290kg/mol

         Fig: 4.9 Dynamic viscosity of model

         Fig: 4.9 specific heat of the model

         Fig: 4.9 Thermal conductivity of the model

      3. Wind pressure of geometry

         Fig: 4.10.1 wind pressure on the body surface is maximum 101519.01 [pa]

         Fig: 4.10.2 this figure shows air is gets deflected because of the slop at the top.

         • Air at bottom is being aspirated by front flat surface as it flows below vehicle and vacuum is created at back because of the flat rear end.

         • Back side car is created cavity it will reduce car speed.

         • This design of car requires more fuel consumption.

         • This type of car design is not safety because havent stability handling.

   3. ASSUMPTIONS ORIGINAL MODELS

      Fig: 5 Original models

      • Vehicle running at 57mph

      • Check for air flow condition

      • External flow parameter study

      1. Boundary Conditions

         2D Plane flow	None
         At X min	Symmetry
         At X max	Default
         At Y min	Default
         At Y max	Default
         At Z min	Default
         At Z max	Default

         1. Ambient condition

            Thermodynamic parameters	Static pressure : 101325.00pa Temperature : 293.20 K
            Velocity parameters	Velocity vector Velocity in X direction :0 mile /h Velocity in Y direction :0 mile /h Velocity in Z direction : – 55.000000mile/h
            Turbulence parameters	Turbulence intensity and length Intensity : 0.10% Length :8.337e-004m

      2. Calculation mesh

         1. Basic mesh dimensions

      Number of cells in X	12
      Number of cells in Y	18
      Number of cells in Z	59

      1. Number of cells

         Total cells	13528
         Fluid cells	12691
         Solid cells	152
         Irregular cells	0
         Partial cells	685
         Trimmed cells	0

      2. Maximum refinement level: 1

         Nam e	Unit	Valu e	Progr ess	Use in converge nce	Delta	Crit eria
         Drag	p	-26.	100	On	0.115	4.63
         		529			37746	969
         					6
         Lift	p	-3.	100	on	0.702	0.76
         		822			10402	063
         					8

      3. Max/Min Table

         Name	Minimum	Maximum
         Pressure [pa]	100951.23	103167.23
         Temperature [K]	293.09	293.76
         Density (fluid) [kg/m3)	1.20	1.26
         Velocity [mile/h]	0	61.5423196
         Velocity X [mile/h]	-22.0655005	23.6210812
         Velocity Y [mile/h]	-35.0755090	36.0758794
         Velocity Z [mile/h]	-61.4800224	5.7181535
         Temperature (fluid ) [K]	293.09	293.46
         Mach number	0	0.08
         Vortices [1/s]	0	3308.641
         Shear stress [pa]	0	4.27
         Relative pressure	-374.91	1798.28
         Heat transfer coefficient [w/m2/K]	0	0
         Surface heat flux [W/m2]	0	0

      4. Engineering database Air Path: gases pre-defined Specific heat ratio (cp/cv): 1.399 Molecular mass: 0.0290 kg/mol

         Fig: 5.6.1 dynamic viscosity of the model

         Fig: 5.6.2 specific heat of the model

         Fig: 5.6.3 Thermal conductivity of the model

      5. Flow simulation of Co2 car design

         Fig: 4. 7.1 Flow simulation of Co2 car design

         Fig: 4. 7.2 Flow simulation of Co2 car design

         • Reduce the fuel consumption.

         • Reduce the drag and lift rate.

         • Improvement of driving characteristics.

         • Increasing speed and efficiency of the car.

      6. surface pressure [pa]

      Fig: 5.8.1 3-D view of surface pressure [pa]

      Fig: 5.8.2 Side view of surface pressure [pa]

   4. COMPARISON FOR OLD DESIGN AND NEW DESIGN.

      OLD DESIGN Lift & drag is maximum
      Goal name	Unit	Value
      Drag	p	-32.8242701
      Lift	p	-12.0434561

      NEW DESIGN lift & drag is minimum
      Goal name	Unit	Value
      Drag	p	-26.59619726
      Lift	p	-3.916694302

   5. CONCLUSION & FUTURE SCOPE

Drag and lift parameter is largely reduced in this study due to the change in the body design and addition of curves and drafts on the flow surface of the Co2 Car surface.

Further the study can be optimised for better results by further modifying the body and/or adding the aerofoil at the tail end and/or changing the rear end geometry to have a flow directional curved shape.

REFERENCES

1. Jump up^ [1] Tuncer Cebeci, Jian P. Shao, Fassi Kafyeke, Eric Laurendeau, Computational Fluid Dynamics for Engineers: From Panel to Navier-Stokes, Springer, 2005, ISBN 3-540-24451-4

2. Jump up^ Proceedings: Institution of Mechanical Engineers (Great Britain). Automobile Division: Institution of Mechanical Engineers, Great Britain (1957)

3. Jump up^ C. Michael Hogan & Gary L. Latshaw, The relationship between highway planning and urban noise, Proceedings of the ASCE, Urban Transportation Division specialty conference, May 21/23, 1973, Chicago, Illinois. by American Society of Civil Engineers. Urban Transportation Division

4. Jump up^ Larry Mayfield (c. 2013), Index to Coefficient of Drag for Many Vehicles Plus Index to Horsepower vs Speed Curves

5. Jump up^ "Volkswagen CarScene TV: Volkswagen XL1 – Vision wird Realität (in german)". Youtube.com. 2011-02-03. Retrieved 2013-06-19.

6. Jump up^ "Background Research." Automobile Aerodynamics. 18 May 2008. DHS. 18 May 2009 <http://web- aerodynamics.webs.com/backgroundresearch.htm>.

BIOGRAPHIES

Anjappa SB he main author is an Asst. Professor in Mechanical Engineering Department, Sree Chaitanya College of Engineering Telangana India. He got his

M. Tech in Thermal Engineering from visvesvaraya Technological University Karnataka India,

Satish Shegedar is a post-graduate in Machine Design JNTU Hyderabad Telangana India; Author is currently working as an assistant professor in the Department of Mechanical Engineering, sree Chaitanya College of engineering Telangana

G Naveen Raju is a post-graduate in Engineering Design JNTU Hyderabad Telangana India; Author is currently working as an assistant professor in the Department of Mechanical Engineering, sree Chaitanya College of engineering Telangana

Vinay Thallapally is a Master of Science in Mechanical Engineering Bridgeport University in USA; Author is currently working as an assistant professor in the Department of Mechanical Engineering, sree Chaitanya College of engineering Telangana