kit MFL 2 V3

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Kit MFL 2 
V3 
Arrasto 
20,5
A A
F C V A
0,727
Re
f
x
C 
5,5
Rexx


5,0
Rexx


0,664
Re
f
x
C 
1,328
2 ( )
Re
A f
L
C c L 
1/7
0,027
Re
f
x
C 
1/7
0,16
Rexx


2.5
2.5
2,87 1,58log
1,89 1,62log
f
A
x
C
L
C




 
  
 
 
  
 
1/7
0,031 7
( )
Re 6
A f
L
C c L 
1,454
2 ( )
Re
A f
l
C c L 
Prandtl Turbulenta 
Blasius laminar 
Kármán laminar 
Rugoso 
5
1/ 7
6
1/ 7
0,031 1.440
, Re 5 10
Re Re
0,031 8.700
, Re 3 10
Re Re
trans
L L
A
trans
L L
C

  

 
   

Transição 
Re /VL
Água a 15 ºC 
 = 1,14.10-3 N.s.m-2,  = 1,14.10-6 m2s-1 
20,5
f
C V
Crr 
b 
(mm) 
Description 
0.0002 to 
0.0010 
0.5 Railroad steel wheel on steel rail 
0.1 Hardened steel ball bearings on steel 
0.0022 to 
0.005 
production bicycle tires at 120 psi 
and 50 km/h, measured on rollers 
0.0025 
Special Michelin solar car/eco-
marathon tires 
0.0055 
Typical BMX bicycle tires used for 
solar cars 
0.010 to 
0.015 
Ordinary car tires on concrete 
0.055 to 
0.065 
Ordinary car tires on grass, mud, 
and sand 
0.3 Ordinary car tires on sand 
,at rol rr
b
F W C W
r
Sustentação 
2
,
0.5
S
S p
p
F
C A cdb
V A
,max
2
estol
S p
P
V
C A
,max 2
min0.5
S
p
P
C
V A
2
0
0
0,6 0,9
S
Atot Ap A
C
C C C
e RA
e
intAtot A Ai Ap A
C C C C C
NACA 
23015 
e 
662-215 
Fig. 9.17, Fox e McDonald: 
coefs. de sustentação e arrasto 
aerofólios 2D 
Ar a 15 ºC e Patm 
 
Rg = 287 m
2s-2 K-1, k = 1,400,  = 1,79.10-5 N.s.m-2, 
 = 1,46.10-5 m2s-1, cv = 718 m
2s-2 K-1, cp = 1.005 m
2s-2 K-1