Forced Convection of Inner Pipe Surface | Online Calculator

Convection Film Coefficients Calculators







Convection Film Coefficient of an Internal Pipe Surface

The heat transfer of pipe inner surface is calculated using the similarity equation:

Nuf = 0.15 × Ref0.33 × Pr0.43 - at laminar flow;

Nuf = 0.021 × Ref0.8 × Pr0.43 - at turbulent flow;

Rel - Reynolds number, Pr - Prandtl number.

In this calculation, the process of heat transfer from the pipe inner surface of diameter D is considered. The surface is in contact with a fluid flow with dynamic viscosity μ, density ρ, thermal conductivity λ and specific heat Cp. The flow runs through the pipe with an average velocity W.

As a result of calculations, the convective film coefficient α of pipe inner surface is determined. In addition, similarity criteria for a given design case are determined, including Reynolds number Re, Prandtl number Pr, Peclet number Pe and Nusselt number Nu.

Convection Film Coefficient of the Internal Pipe Surface
calculation of Convection Film Coefficient of the Internal Pipe Surface

INITIAL DATA

D - Pipe inner diameter;


w - Flow rate;


μ - Dynamic fluid viscosity;


ρ - Fluid density;


λ - Thermal conductivity coefficient of a fluid;


Cp - Specific heat of a fluid.

RESULTS DATA

α - Convection film coefficient of pipe surface.


Re - Reynolds number.


Pr - Prandtl number.


Pe - Peclet number.


Nu - Nusselt number.

Diameter (D)

Flow rate (w)

Dynamic viscosity (μ)

Density (ρ)

Thermal conductivity (λ)

Specific heat (Сp)

Film coefficient (α)

Reynolds number (Re)

Prandtl number (Pr)

Peclet number (Pe)

Nusselt number (Nu)

BASIC FORMULAS

Reynolds number:

Re = ρ*w*D / μ;

Peclet number:

Pe = Сp*ρ*w*D / λ;

Prandtl number:

Pr = Pe / Re;

Nusselt number:

Nu = 0.15*Re0.33*Pr0.43 - at laminar flow;
Nu = 0.021*Re0.8*Pr0.43 - at turbulent flow;

Convection film coefficient:

α = Nu*λ / D.

INITIAL DATA

D - Pipe inner diameter;


w - Flow rate;


μ - Dynamic fluid viscosity;


ρ - Fluid density;


λ - Thermal conductivity coefficient of a fluid;


Cp - Specific heat of a fluid.

RESULTS DATA

α - Convection film coefficient of pipe surface.


Re - Reynolds number.


Pr - Prandtl number.


Pe - Peclet number.


Nu - Nusselt number.

FLUID PROPERTIES

Fluid properties at 20ºC (68 ºF)

Fluid

Density

Kg/m³

(lb/ft³)

Dynamic viscosity

Pa*s

(lb*s/ft²)

Volumetric

expansion

1/ºC

(1/ºF)

Thermal

conductivity

W/m*ºC

(W/in*ºF)

Specific heat

J/kg*ºC

(J/lb*ºF)

Water

998

(62.3)

0.001

(0.0000209)

0.00021

(0.00016)

0.599

(0.084)

4182

(1053)

Air

1.205

(0.075)

0.000018

(0.000000377)

0.00365

(0.00202)

0.0259

(0.00036)

1005

(253)

Water vapor

0.01

(0.00063)

0.0000096

(0.0000002)

0.00365

(0.00202)

0.0178

(0.00025)

1859

(468)

Engine Oil SAE

15W-40

879

(54.9)

0.287

(0.006)

0.00655

(0.0036)

0.134

(0.00190)

2039

(513)

Fluid properties at 40ºC (104 ºF)

Fluid

Density

Kg/m³

(lb/ft³)

Dynamic viscosity

Pa*s

(lb*s/ft²)

Volumetric

expansion

1/ºC

(1/ºF)

Thermal

conductivity

W/m*ºC

(W/in*ºF)

Specific heat

J/kg*ºC

(J/lb*ºF)

Water

992

(62)

0.00065

(0.0000135)

0.00021

(0.00016)

0.635

(0.0090)

4170

(1050)

Air

1.128

(0.07)

0.000019

(0.000000397)

0.00365

(0.00202)

0.0276

(0.00039)

1005

(253)

Water vapor

0.05

(0.0031)

0.0000104

(0.000000217)

0.00365

(0.00202)

0.0195

(0.000275)

1860

(468)

Engine Oil SAE

15W-40

866

(54.1)

0.091

(0.0019)

0.00655

(0.0036)

0.131

(0.00184)

2106

(530)

Fluid properties at 60ºC (140 ºF)

Fluid

Density

Kg/m³

(lb/ft³)

Dynamic viscosity

Pa*s

(lb*s/ft²)

Volumetric

expansion

1/ºC

(1/ºF)

Thermal

conductivity

W/m*ºC

(W/in*ºF)

Specific heat

J/kg*ºC

(J/lb*ºF)

Water

963

(60.2)

0.00046

(0.0000096)

0.00021

(0.00016)

0.659

(0.0093)

4184

(1054)

Air

1.060

(0.066)

0.000020

(0.00000042)

0.00365

(0.00202)

0.0290

(0.00041)

1005

(253)

Water vapor

0.14

(0.0088)

0.0000112

(0.00000023)

0.00365

(0.00202)

0.0212

(0.00029)

1870

(471)

Engine Oil SAE

15W-40

853

(53.3)

0.038

(0.00079)

0.00655

(0.0036)

0.129

(0.00180)

2165

(545)

Fluid properties at 80ºC (176 ºF)

Fluid

Density

Kg/m³

(lb/ft³)

Dynamic viscosity

Pa*s

(lb*s/ft²)

Volumetric

expansion

1/ºC

(1/ºF)

Thermal

conductivity

W/m*ºC

(W/in*ºF)

Specific heat

J/kg*ºC

(J/lb*ºF)

Water

972

(60.7)

0.00035

(0.0000073)

0.00021

(0.00016)

0.675

(0.0095)

4196

(1057)

Air

1.00

(0.063)

0.000021

(0.00000044)

0.00365

(0.00202)

0.0305

(0.00043)

1009

(254)

Water vapor

0.29

(0.018)

0.0000119

(0.00000025)

0.00365

(0.00202)

0.0229

(0.00032)

1880

(474)

Engine Oil SAE

15W-40

841

(52.6)

0.019

(0.00039)

0.00655

(0.0036)

0.127

(0.00178)

2227

(561)

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