# parameters

Module containing parameters used in the convective heat transfer modules.

Controller: **CodeCogs**

## Interface

C++

Excel

## Overview

This module contains parameters which are used in studying various convective heat transfer phenomena.## References:

Fluid Properties Calculator giving the values of the kinematic viscosity , thermal diffusivity and thermal expansion coefficient , for fluids at various temperatures: [url]http://www.mhtl.uwaterloo.ca/old/onlinetools/airprop/airprop.html[/url]### Authors

*Grigore Bentea, Lucian Bentea (November 2006)*

## Prandtl

doublePrandtl( | double | mu | |

double | a | )[inline] |

### Example 1

- The code below computes the Prandtl number in the case of Ethylene Glycol at 17 degrees Celsius.
#include <codecogs/engineering/heat_transfer/convection/parameters.h> #include <stdio.h> int main() { double mu = 2.1936E-5, a = 9.3834E-8; printf("\nEthylene Glycol at 17 deg. Celsius\n\n"); printf("Pr = %.4lf\n\n", Engineering::Heat_Transfer::Convection::Prandtl(mu, a)); return 0; }

### Output

Ethylene Glycol at 17 deg. Celsius Pr = 233.7745

### Parameters

mu the kinematic viscosity (sq. meters per second) a the thermal diffusivity (sq. meters per second)

### Returns

- the Prandtl number for the fluid with given parameters

##### Source Code

Source code is available when you agree to a GP Licence or buy a Commercial Licence.

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## Grashof

doubleGrashof( | double | mu | |

double | beta | ||

double | dT | ||

double | L | )[inline] |

### Example 2

- In the following example the Grashof number is calculated for air at 25 degrees Celsius going through a pipe at 15 degrees Celsius with internal diameter of 0.1 meters.
#include <codecogs/engineering/heat_transfer/convection/parameters.h> #include <stdio.h> int main() { double mu = 1.5571E-5, beta = 3.3540E-3, dT = 10, L = 0.1; printf("\nAir at 25 deg. Celsius\n\n"); printf("Gr = %.4lf\n\n", Engineering::Heat_Transfer::Convection::Grashof(mu, beta, dT, L)); return 0; }

### Output

Air at 25 deg. Celsius Gr = 1356596.6005

### References

- Dan Stefanescu, Mircea Marinescu - "Termotehnica"

### Parameters

mu the kinematic viscosity (sq. meters per second) beta the thermal expansion coefficient (1 / Kelvin) dT the temperature difference (Kelvin) L the characteristic length (meters)

### Returns

- the Grashof number for the fluid with given parameters

##### Source Code

Source code is available when you agree to a GP Licence or buy a Commercial Licence.

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## Reynolds

doubleReynolds( | double | mu | |

double | w | ||

double | L | )[inline] |

### Example 3

- In the following example the Reynolds number is computed for carbon dioxide at 75 degrees Celsius going through a pipe with internal diameter of 1.5 meters, having a velocity of 5 meters per second.
#include <codecogs/engineering/heat_transfer/convection/parameters.h> #include <stdio.h> int main() { double mu = 1.1203E-5, velocity = 5, length = 1.5, Re = Engineering::Heat_Transfer::Convection::Reynolds(mu, velocity, length); printf("Carbon Dioxide at 75 deg. Celsius\n\n"); printf("Re = %.4lf\n", Re); if (Re < 2000) printf("Laminar flow.\n"); else if (Re > 4000) printf("Turbulent flow.\n"); else printf("Unpredictable flow (critical zone).\n"); printf("\n"); return 0; }

### Output

Carbon Dioxide at 75 deg. Celsius Re = 669463.5366 Turbulent flow.

### References

- The Engineering Division, Crane Co., "Flow of fluids through valves, fittings, and pipe", Chicago, 1957

### Parameters

mu kinematic viscosity of fluid (sq. meters per second) w mean velocity of flow (meters per second) L characteristic length (meters)

### Returns

- the Reynolds number corresponding to the given parameters

##### Source Code

Source code is available when you agree to a GP Licence or buy a Commercial Licence.

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