Team Cool Car

ME 4182 Final Presentation

December 3rd, 2014Ryan Simpson

Rachit Kansal

Rohith Desikan

Jessica Renner

Mitra Hosseini

Final Complete Design

Gantt Chart

● Hot summer weather

o Cars heat up extremely quickly

o Cabin temperature can exceed 40 F

of ambient temperature

o Very dangerous due to greenhouse

effect

● Internal car cooling methods are not

effective

o Window tinting/sunshades

o Parking in shaded areas

o Cracking windows open

User Need

● US 3943726 A

● US 5373703 A

● US 4813238 A

● US 4983314 A

● US 5005367 A

Competitive Products

● Ideal market locations for 2 concepts:

o Regions with humidity levels ranging from 50-95%

With relatively low rain

and/or

o Regions with average summer temperatures of 80-110ºF

With expendable water supplies

● Other factors to consider:

o Are cars the primary mode of transportation?

o Could we adapt this for public transit? Residences?

Market

Stakeholder Matrix

Function Tree

Design Needs/House of Quality

Specification SheetChanges D/W Requirement Value Source

Functionality

09/16/2014 D Fast-acting 3ºC/min Team

09/16/2014 D Maximum operating ambient temperature 60ºC Team

09/16/2014 D Minimum operating ambient temperature 15ºC Team

09/16/2014 D Target surface temperature (seats, belts, dashboard, steering wheel) ~30ºC Standard

09/16/2014 W Target ambient air temperature in cabin ~30ºC Team

09/16/2014 D Minimum permissible cabin temperature after use >10ºC Team

09/16/2014 D Detachable by hand Team

Geometry

09/16/2014 D Maximum length <1.25 m Standard

09/16/2014 D Maximum width <2.00 m Standard

09/16/2014 W Low profile (height) <0.10 m Team

09/16/2014 D Lightweight <6.8 kg Standard

Cost

09/16/2014 D For consumer <$60 Customer

Discovery

Operation

09/16/2014 D Initialize and terminate automatically or by remote communication Team

09/16/2014 D Terminate upon desired cabin temp, energy use limit, OR safety shut off

criteria

Team

Changes

D/W

Requirement Value Source

Safety

09/16/2014 D Maximum permissible cabin temperature after product use 40ºC Team

09/16/2014 D Maximum product temperature <30ºC Standard

09/16/2014 D No sharp edges or dangerous parts Standard

09/16/2014 D Tamper-free and anti-theft integrated mechanisms Team

09/16/2014 D Withstand torque associated with vehicle speeds of up to 70 mph Team

Maintenance/Installation

09/16/2014 W Time for installation < 1 hour Team

09/16/2014 W Reversible assembly Team

09/16/2014 W Minimum number of operating cycles (Lifetime) 10,000

Materials

09/16/2014 W Preventative: Low thermal conductivity <1 W/m^2-K Team

09/16/2014 W Preventative: High specific heat >500 J/kg-K Team

09/16/2014 W Corrective: High thermal conductivity >5 W/m^2-K Team

09/16/2014 W Corrective: Low specific heat <500 J/kg-K Team

Morphological ChartFunction 1 2 3 4 5 6

Corrective -

Surfaces

Water Evap

(windshield

)

Ice on

windshiel

d

TEC on

surface

Air

circulation

Endothermic

reaction

turn on ac

early

Corrective -

Ambient

Water Evap

(windshield

)

air

circulation

turn on ac

early

magnetic

refrigeration

open sun-

roof/window

mist

sprayed

into air

Preventive -

Convective

insulative

surface

cover

air curtain hard canopy fluid canopy vacuum

insulation

Preventive -

Radiative

one-layer

sunshade

multi-

layer

sunshade

insulative

surface

cover

hard canopy variable

opacity

windshield

fluid

canopy

Operate in

Ta < 120

materials

with high

Tmelting

feedback

loop

insulate

battery/elect

ronics

ask user for

input

connections

not

dependent

on T

accomodate

for thermal

exp.

Self-

powered

solar

attachment

integrated

solar

panels

stirling

engine

TEC's battery

attachment

integrated

battery

Start/Stop button timer toggle

switch

app temp sensor accel

sensor

Morphological ChartFunction 1 2 3 4 5 6

Portability handles collapsibility lightweight retractingshape/geom

for carrying

Lightweightlight

materialshollow porous

minimal

parts

separate

parts

minimal

assembly

attachment

Theft/tamper

proofinside car self-contained

physical

locks

password

locktext msg

link to car

keys

Reversible

Installationclip on friction joints snap fit magnetic button adhesive

Aesthetics color slim form hiddenlow

profileaerodynamic

matching

materials

UI knobs digital screen buttons app lights text msg

Acousticssound

dampening

sound

cancelling

minimize

vibes

minimize

moving

parts

Error

Indicatorssounds lights txt app

material

indicatorthrough UI

Battery Status lights gauge car's UI system UI app text/email

Top Ideas from Morphological Chart

Concept Design and Selection

Concept Design and Selection

● Heat Transfer Modeling on MATLAB experiencing difficulties.

● Independently would need too much mass of water

Water Reservoir

● Qnetrad = (αw x G) – (ε x σ x αw x Twin4)

● Qcondw = (kw x (Tw - Twin))/thickness

● Qnetconv = hfree .x (Tw - Tamb)

● Qout = Qnetrad + Qcondw + Qnetconv

● Qdot = Qout x 1.599

● mdoutloss = -Qdot/Ewater

● Masslost8hrs = mdotloss x 3600 x 8

Water Reservoir Equations

Air Curtain Energy Modeling: Steady State

1. Determine incoming solar radiation

1. Determine convective heat transfer in from surroundings

1. Use above to determine total heat in

1. Equate dissipated heat by air curtain to total heat in

1. Determine air curtain’s ‘h’ value

1. Determine corresponding air curtain speed

Steady State Equations

1. Qrad_in = G x twind x (1- (ρshade x twind))

2. Qconv_in= hfree x A x (Ts-Tamb)

3. Qin = Qrad_in+Qconv_in

4. Qdisp = Qin

5. Qdisp = hforced x A x (Twindshield-Tcabin)

6. hforced = 10.45 – v + 10 x √v

Results of Steady-State Model

1. ‘Typical’ summer day constructed for Gradiation and Tambient

1. Loop is created to ‘move’ through typical day

1. Current Gradiation and Tambientvalues pulled

1. Calculations performed and values updated

Air Curtain Energy Modeling: Transient

1. Select Gcurrent and Tambient

1. Calculate Qrad_in

1. Calculate hfree from ΔT

1. Calculate Qconv_in

1. Use ‘v’ to calculate Qdisp

1. Find (Qin-Qdisp)

1. Update Twindshield,Tshade,Tcabin using energy balances

Transient Equations

Results of Transient

Analysis with System

Results of Transient

Analysis without

System

● “ORCA Grow Film”

● Mylar coated bubble reflector

● Aluminum

● Polyurethane

Material Selection for Radiation Shade

Material Reflectance Comparison

● Thickness: 0.0254 mm

● Density: 43106 kg/m3

● Size: 0.88 x 1.47 m

● Cost: $7.44 for the size

o $60 for a 1.37 x 7.62 m roll

● Reflectivity: 0.92-0.95 for IR

Orca Grow Film

● Includes the weight of the sunshade, springs, and cable.

Work = Density x volume x height x sin(windshield angle)

= 6.5165 J

Power = Work/time

= 2.2855 W

where the time for deployment is 10 seconds and the windshield angle is

40º.

Motor Power Analysis

Fan Products

12 V DC Crossflow Cooling Fans

Manufacturer Part No. Power

Draw

Dimensions (in) Weight

(lbs)

Airflow

(cfm)

Price

Stinger SGJ78 0.6 A 1.5 x 5.7 x 6 0.9 N/A $25

McMaster 2087K12 N/A 1 ⅞ x 2 x 10 ⅛ N/A 58 $81

McMaster 19665K2

1

N/A 4 3/16 x 5 ¼ x 6 N/A 230 $44

Xscorpion TF8 N/A 1.8 x 1.8 x 8.2 N/A N/A $21

PAC CF1 0.19 A 1 ¼ x 1 ¼ x 8 ½ 0.85 54 $23

Mouser QG030 0.52 A 1.87 x 1.97 x 5.83 0.56 44 $88

Electronics Circuit Diagram

Final Bill of Materials

3D CAD Modeling

Model of Top Unit

Model of Fans

Exploded View of Top Unit

Model of Bottom Unit

Exploded Animation of the Bottom Unit

Control vs Sunshade

- Sunshade was 8-10 deg lower than control over the

course of the day.

Testing and Results

Pictures

Pictures

Pictures

Pictures

Future Plans

• Find a solution for the sunshade sagging in the

middle (e.g. keep in horizontal tension as it rolls

up).

• Create variability in design for various car and

customer styles/preferences.

Thank you

Questions?