COMPUTER AIDED DESIGN (CAD)

COMPUTER  AIDED  DESIGN

Computer  aided  design  is  used  of   computer  system  to  assist  in  the   creation,  modification ,  analysis , and  optimisation  of  a  design. CAD  software  is   used  to   increase  the  productivity  of  the  designer  ,  improve  the  quality  of  design  ,  improve  communication  through  documentation.  and  to create  a  database  for  manufacturing , 

     

            It  is  used  in  many  fields  its  used  in  desgnining   electronic  system  known  as  electronic  design  automation .  In  mechanical  design  it  is  known  as  mechanical   design  automation CAD

which  include  the  process  of  creating  a  technical   drawing with  the   use  of  computer  system . 

             CAD  may  be  used   to  design  curves  and  figures  in  two  dimensional  or  curves ,  surfaces  and  solid  in  three  dimensional  space .

               CAD  used  in  many  applications like  ship  building  ,  aerospace  industries ,  CAD  is  also  wide  to  produce  computer  animation   for  special  effects  in  movies  .

USES  OF  CAD 

CAD   is  one  of  many  tools  used  by  engineers  and  designers  .  It  is  also  used  for the  accurate  creation  of  photo simulation   that  are  often  required  in  the  preparation   of  environment  impacts  reports .

             

SHEAR FORCE AND BENDING MOMENTS

SHEAR  FORCE

Shear  force  is  defined  as  the  pushing  one  parts  of  body  to one  side  and  another  parts  of  body  in  other  direction  . When  are forces  aligned  to  each  other  than  it  is  called  compression  force.  

         An  example  is  deck of   cards  being  pushed  in  one  of  the  top  and  another  to  the  bottom ,  causing  the  cards  to  slides .

BENDING  MOMENTS 

A  bending  moment  is  a  reaction  induced  in  a  structural  moments   when  external  force  is applied  to  the  elements  causing  the  elements  to  bends .  The  most  common  element  of  bending  moments  is  beam .  Beam  can  also  have  one  end  fixed  and  one  end  simply  supported .  The  simplest     type  of  beam  is  cantilever  which   is  fixed  with  one  end  and  is free from other  end .

SYSTEMS BOUNDARY AND SURROUNDING

SYSTEM

A   system  is  defined  as  a  region  in  space  containing  a  specific   amount  of   matter  whose  behavior  is   being  observed .

The  system  is  separated  from surrounding  by  its  boundary .  The  boundary  may  be  real  one  or  imaginary  surface .

 

The  boundary  may  be  in  rest  or in  motion  and  can   change  his  shape  and  size .The  term  surrounding  is  restricted  to  those  portion  of  the  matter  external  to  the  system  in  which  is  thermodynamics  affected  by  the  changes  occurring  within  in  the  system.

TYPES  OF  SYSTEMS    

1. OPEN  SYSTEM  

                                   It  is the  region   in   space   defined  by  boundary  across  in  which   matter  is  flow  in  the  form   of  heat  and  work  . 

    EXAMPLE  OF  OPEN  SYSTEM 

•                    Water  entering  boilers  and  leaves  as  a  stream 
•                    Gases  flowing  through  turbines 
•                     Gas  expending  from  pressurized   container  through  a  nozzle .

2 .  CLOSED   SYSTEM

                                It  is  a  system  in  which   no   mass  crosses  the  boundary .  that  is  quantity  of  matter    within   the   system  remain  fixed   .  But  energy  is  allow  to  cross  the  boundary  in  the  form  of  heat  and  work  .

    EXAMPLE  OF  CLOSED  SYSTEM

             

• Gas  expending  in  a  piston  cylinder  
• mixture  of  water  and  stream  in  closed   vessel 

3 . ISOLATED  SYSTEM

                                A  system  is  termed  as  isolated  if  neither  matter  or  energy  is  allow   to  transfer  to  across  the  boundary . 

       EXAMPLE  OF  ISOLATED  SYSTEM 

QUASISTATIC PROCESS

QUASISTATIC  PROCESS

In  thermodynamics  a  quasistatic  process is  a   thermodynamic  process ,  that  happens   infinitely  slowly . 

 

No  real  process  is  quasistatic  but  some  processes  can  be  approximated  by  performing   them   very   properly.

 

Any  reversible   process   is   a   necessirily  a  quasistatic  one  , However  some   Quasistatic   process   are   irreversible .  If  there   is   a   heat  flowing  (in  or   out  of   the   system)   or  entropy  is   being  created   in  such  a  way  .  An  example  of  a  Quasistatic   process  that  is   not  reversible  is  a  compression  against  the  system  with  a  piston  subjected  to  friction  --  although  the  system  is  always   in  thermal   equilibrium  .

            The  notable  example  of  a  process  that  is  not  even  Quasistatic   is  the  slow  heat  exchange  between  two  bodies  at  two  different  finitely  temperature  where  the  heat  exchange  is  controlled   by  adiabatic  process.

            The  states   of  the  two  bodies  are  never  infinite  close  to  equilibrium  .  since thermal  equilibrium  requires  that  the  two  bodies  at  the  same  temperature.    

EQUILIBRIUM

EQUILIBRIUM 

The  condition  of   system   in   which   all  competing  system   are  in  balance.

LIST  OF  TYPES   OF  EQUILIBRIUM  

1. MECHANICAL  EQUILIBRIUM  

                                           A  mechanical  equilibrium   is  a   state   in  which    momentum  of  a  particle ,  rigid   body ,  system   are  conserved  and  net  force  zero .

                                         F = 0

                                          In  the   specific  case  linear  momentum  is  zero  and  conserved  is  said  to  be  static  equilibrium .

                 EXAMPLE    when  a  person  press  a  spring, 

2.  CHEMICAL  EQUILIBRIUM  

                                     The  state  in  which  the  concentration  of  the  reactants  and  products  have  stopped  in  time . This  states  results  when  the  forward  reaction  proceeds  at  the  same  rate  as  the  reverse  reaction. 

3.  THERMAL  EQUILIBRIUM 

                                               A   state  where  an  object  and  its  surrounding  cease  to  exchange  energy  in  the  form  of  heat  it  means  they  are  in  same  temperature.  Thermal  are  obeys  zeroth  law  of  thermodynamics . System  in  thermodynamic  equilibrium  always  in  thermal  equilibrium.   

4.  THERMODYNAMIC  EQUILIBRIUM 

                                                           The  state  of  thermodynamic  system  which  is  in  thermal  ,  mechanical  and  chemical  equilibrium  . when  it is  said  that a  system  is  simple  in  equilibrium .

    

HYDRAULIC MACHINE

HYDRAULIC  MACHINE 

• It  is a  tools  that  used  liquid  fluid  power  to  do  simple  work.
• Heavy  equipment is   a  common  examples  of  this  types   of  machine.
• Hydraulic  fluid  are  transmitted  through  machines  to  various  hydraulic  motors  and  hydraulic  cylinders  .
• The  fluid  is  directly  control  by  control  waves  and  distributed  through  tubes.
• In  this  machines  very  large  amount  of   power  is  transmitted  through  small  tubes.
• Hydraulic  machines  is  operated  by  the  use  of  hydraulics.

• FORCE  AND  TORQUE  MULTIPLICATION 

          A  fundamental  feature   of  hydraulic  system  is  ability  to  apply   force  or  torque                          multiplication  in  easy  way,  without  the  need  of  mechanical  gears.  

• CONSTANT  PRESSURE  AND  LOADING  SENSING  SYSTEM 

1. CONSTANT  PRESSURE  SYSTEM

                                                             Pump  pressure   always  equal  to  the  pressure  setting   for  the  pump  regulator. This  setting  must   cover  the  maximum  required   load  pressure.

  

2.  LOADING  SENSING  SYSTEM

                                                          It  generate  less  power   losses  as  the   pump  can  reduce  the  both  flow  and  pressure   to  match  the   load  requirement .  It  also  require  additional  logical  valves .  It  generate  a   constant  power  loss   related  to  regulating  pressure.

• COMPONENTS  

1.   HYDRAULIC  PUMP  

      Hydraulic  pumps  supply  fluid  to  the  components  in  the  system. Pressure  in   the  system             develop  in  the  load.  Pump  have  a  power  density  about  ten  times  greater  than  electric               motor.  They  are  powered  by  electric  motor  connected  through   gears  reduced  vibration.

   

2.  CONTROL  VALVES  

     They  are  usually  consists  of  spool  inside  the  caste  iron  .  directional  control  valves  are            designed  for  stackable  with  one  valve  for  each  hydraulic  cylinder.

3.  ACTUATOR 

• Hydraulic  Cylinder 
• Hydraulic  Transmission  
• Brakes
• Hydraulic  Motor

FLUID MECHANICS

FLUID  MECHANICS 

• It  is  a  branch  of  physics  which  involves  the  study  of  fluid  like  liquid, gas, plasmas   and   the   forces  on  them .
• The  FLUID  MECHANICS  is  divided   into  fluid  statics  and  fluid  dynamics .
• The  fluid  statics  tells  the  study  of  fluid  at  rest .
• The  fluid  dynamics   tells  the  study  of  effect  of  forces  on  fluid  motion.
• It  is    branch  of   continuum  mechanics  , a  subject  without  model matter  without  information  that  is  made  up  of  atoms  that  is , it  model  matter 

 

FLUID  STATICS 

                                  The  fluid  statics  is  the  branch  of  fluid  mechanics  which  deals  with  the  study  of  fluid  at  rest  .  Condition  under  which  fluid  at  rest  are  in   stable  equilibrium  .Fluid  mechanics  is  fundamental of  hydraulics. 

FLUID  DYNAMICS 

                            The  fluid  dynamics  is a  part  of  fluid  mechanics  which  describes  the  fluid  flow. The   nature  science  of  fluid  in  motion.  It  includes  the  aerodynamics  (study  of  gases  and  air  in  motion)  and  hydrodynamics  (study  of  liquid  in  motion) .  Fluids  dynamics  has  a  wide  range  of  application ,  including  calculating  forces  and  moments  on  aircraft.

PRESSURE

PRESSURE

DEFINITION 

•   It  is  the  force  applied  perpendicularly  to  the  surface  of  an  objects  per  unit  area  over   which  that  force  is  disturbed .
• Various   units  are  used  to   excess  pressure.
• SI  unit  of  pressure  is  pascal 
• Pressure  may  be  expressed  in  terms   of   standard   atmospheric  pressure.  The  atmosphere  is   equal   to   the   pressure.

FORMULA

P =  F/A

  Where   p  is  pressure  

                f  is  force 

                a   is  area

  

  Pressure   is  a   scalar  quantity. 

UNITS

• The SI unit  of  pressure  is  pascal,  equal  to  one  newton  per  square  meter.
• The  CGS  unit  of  pressure  is  BARYE(ba),  equal  to  0.1 pa
• Sometimes  pressure  express  in  gram  force  or  kilogram.

EXAMPLES

• A  finger  can  be  pressed  against    the  wall   without  making  any  lasting  impression.
• Pressure  is  transmitted   to  solar  boundaries  of  fluid  normal   to  these  boundaries  or  section  at  every  point.

    

HEAT TRANSFER

HEAT  TRANSFER

• Exchange  the  thermal  energy  by   physical  systems.
• The  fundamental  modes   of  heat  transfer  is  conduction, diffusion, radiation, convection.
• Heat  transfer  occur  region  from  a  high  region   to  high  temp.  to   the  region  a  lower   temp..
• Heat  transfer  changer  internal  energy  according  to  first  law  of  thermodynamics.
• The   second  law  of  thermodynamics  defined  the  concepts  of  thermodynamics  entropy,  by  measurable heat  transfer.  

HEAT  EQUATION

The  heat   equation  is  a  partial  differentiation  equation   that   describes  the  distribution  of   heat  in  a  given   region  of  time.  In  some  cases  the  exact  equations  are  available.  In   other  cases   the   equation  must  be  solve  by  computing  methods.

HEAT   EXCHANGER 

The  heat  exchanger  is  used  for   more  efficient  heat   transfer.It  is   used  in  refrigeration, air  conditioning, space  heating ,  power  generation,  Common  type  of  heat   exchangers  flows  include  parallel  flow,  counter  flow.  

HEAT  TRANSFER  IN  A  HUMAN   BODY

The  principles  of   heat  transfer  in  engineering  systems  can  be   applied    to  the   human  body  in  order   to   determine  how  the  body   is   transfer. Heat  is  producing  continuously  in  body  metabolism  of  nutrients  which   provides  energy  to  the  system.The   human  body  must  maintain  a   constitent  in  order  to  maintain  healthy  bodily  function. Heat  transfer  occur  more  in  body  when  when  the  temperature  of  surrounding  is  significantly  less  than  the  normal  body  temperature.The  normal  body  temperature  is  approximately  37;c.      

REFRIGERATION

REFRIGERATION

• It  is  the   process  to  moving  heat   from  one   location  to   another.
• The  work  of  heat   transfer  is  traditionally   driven  by  mechanical  work.
• It  has  many  application  included   but  not  limited  to  household  refrigerators,  industrial  freezers,  and  air   conditioning.
• It  has  a   large   impact   on  industries.

COMMERCIAL   USES

• In  1842   JOHN  GORRIE  created  a  system  capable  of   refrigerating  water  to  produce  ice.
• Although  it  was  a  commercial  failure .
• Refrigerated  railroad  cars  was  introduced   in   the  USA  in  the  1840s  for  short  run  transport of     daily   products.   but  these  use  a  harvested  ice  to  cool  a   temperature.
• The  new  refrigerating  technology  use  to   freeze  meat   supply  for  a  transport  by  sea  from  the  BRITISH  DOMINIONS  .
• On  15  FEBRUARY  1882  the  DUNEDIN  sailed  for    LONDON  with  what  was  to  be   the  first   commercial  successful  refrigerated  shipping  voyage,  and  foundation  of  the  refrigerated  meat  industries .
• By  the  1890s  the  refrigeration  play   a  vitul  role    in   the   distribution  of    food.
• By  1914,  almost  in  every  location   used  artificial  refrigeration.
• By  the  middle  of  2oth  century   ,  refrigeration  units   were  designed  for  installation  on  trucks  or  lorries .
• Refrigeration  are  used  to   transport   frozen  foods,  fruits  and  vegetables.

AEROMOBIL S.R.O. AEROMOBIL (flying car)

AEROMOBIL

• The  AEROMOBIL  S.R.O. AEROMOBIL  is  a  Slovak  prototype   roadable  aircraft . 
•   Designed  by  STEFAN  KLEIN 
• First  flown  in  2013
• The  aircraft  is  produced  by   aeromobil  s.r.o  company.
• Aeromobil  co- founder  and CEO  is  JURAJ  VACULIK .
• He   indicated  that   in  march  2015   that  the  vehicle  is  intended  for   "wealthy  supercar   buyers and  flight  enthusiast .
• Vaculik   excepts  that  the  aircraft  is  available  for  sale  in  2017.

DESIGN  AND  DEVELOPMENT 

The  prototype  was  conceived  as a vehicle  that  can  be  converted   from  an  automobile  to  an  aircraft.The  version  proof  of  concept   took  20  year  to  develop.  The  prototype   was  constructed   by  the   aeromobil  team, BRATISLAVA   ,SLOVAKIA,  and  lead  co  founder  by  STEFAN  KLEIN  and   JURAJ  VACULIK   advised  by inventor  DEAN  KAMEN.

            As  in  2103  there  are  four  developed  version  1.0, 2.0, 2.5  with  earlier  version   folding  wings.while  later  version  have  folding  wings  and  fins  around  the  wheel . Version  2.5  was  first  exhibited  in  MONTREAL  at  the  SAE aero tech congress  and  exhibition.Version  3.0 was  introduced  at  the  pioneers  festival  2014 in VIENNA,  austria   and  flew  in  OCTOBER.

        In  2014  the  company  said  that  there is  no  date for   a  finished   product.but  after  the   crash  of  the  prototype  ,they  hope  for  deliveries  on  2018.

AERODYNAMICS

AERODYNAMICS

ABOUT  IT

•        It  is  branch  of  fluid  dynamics  deal  with  the  study  of  motion  of  air.
• Aerodynamics  is  a  sub-field  of  fluid  dynamics  and  gas  dynamics.
• Gas  dynamics  is  used   to  study  the  motion  of  all gases,not  limited  to  air.
• Recent  work  in  aerodynamics  has  focused  on  issues  related  to  compressible  flow, turbulence, and  boundary  layer.

FLOW  CLASSIFICATION 

•      Flow  velocity  is  used  to  classify  flow  according  to  speed.
• Compressibility refers  to   whether  or  not  the  flow  in  a  problem  can  have  a  varying  density.
• Subsonic  flows  are  flow  fields  in  which  air  velocity  in  the  entire  flow  is  below  the  local  speed  of  sound.
• Subsonic  flow  are  assumed  to  be  incompressible, i.e  the  density  is  assumed  to  be  constant.

Transonic  flow  include  both  region  of  subsonic  flow  and  a  region  in  which  the  flow  speed  is  greater  than  the  speed  of  sound.

SUPERSONIC  FLOWS

It  is  defined  as  the  flows  in  which  the  flow  speed  is   greater  than  the  speed   of  sound   everywhere.

HYPERSONIC  FLOW

It  refers  to  flow  where  the  flow  speed  is  much  greater  than  the  speed  of  sound.

Viscosity  is  associated  with  the  friction forces  in  a  flow.In  some  flow  fields, viscous  effects  are  very  small, Flows  for  which  viscosity  is  not  neglected  is  called  the viscous  flows.

EXTERNAL  AERODYNAMICS 

It  is  a  study  of  flow  around  solid  objects  of  various  shapes.


INTERNAL  AERODYNAMICS

It  is  the study  of  flow  of  through  passages  in  solid  objects.



CONSERVATION  LAWS  

1. Conservation  of  mass 

                                               In  fluid  dynamics  the  mathematical  formula  of  this  principle  is  known  as  mass  continuity  equation.

2,    Conservation  of  momentum

                                                       In  dynamics  the  mathematical  formula of  this  is  Newtons second  laws.In  its  mst  complete  form  the  momentum  equation  is  known  as  Navies  stokes  equation.This  equation  has  no  unique  solution  and  are  solved  in  modern  dynamics  using computational  techanique.

3. Conservation  of  energy 

                                                     

                                               Any  addition or  substruction  of  energy  is  due  to  neither   to  the  fluid  flow  in  and  not  out  of  the  reason  of  interest.

BRANCHES  OF  AERODYNAMICS

1.  INCOMPRESSIBLE  AERODYNAMICS 

                                                                 It  is  the  flow  in  which  the  density  is  constant  in  both  time  and  space.Although  all real  fluids   are  compressible.Effects  of  compressibility  of more  sufficient  at  speed  close.

2.  COMPRESSIBLE  AERODYNAMICS 

                                                                       According  to  theory  of  dynamics,  a  flow  is  considered  to  be  compressible  if  its  changes  density  with  respect  to  pressure  is  non  zero  along  a  stream  line.This  means  that  unlike  incompressible  flow  changes  in  density  must  be  considered .