Pipeflow

Introduction

In this tutorial, we’ll explore a Python script that calculates the Reynolds number, classifies the flow type, and determines the head loss in pipes. We’ll also learn how to process multiple pipes with different properties. This code is useful for engineers and students who need to analyze fluid flow in pipes.

Prerequisites

Before diving into the code, make sure you have Python installed on your system. If you’re new to Python, you can download it from the official website: https://www.python.org/downloads/

Code Explanation

Let’s break down the code step by step:

Importing the Math Module

import math

The math module is imported to provide access to mathematical functions, such as square roots and trigonometric functions. However, in this specific code, the math module is not used directly.

Defining Variables

pipe_diameter = 0.5 # Diameter of the pipe in meters (m)
pipe_length =100 #Length of pipe in meters(m)
fluid_density = 1000 # density of fluid in kg/m3
fluid_viscosity = 0.002 #Viscosity in Pa.s
velocity = 4 #flow velocity in m/s

These variables represent the properties of the pipe and the fluid flowing through it. The pipe diameter is set to 0.5 meters, the length is 100 meters, the fluid density is 1000 kg/m³, the fluid viscosity is 0.002 Pa·s, and the flow velocity is 4 m/s.

Calculating the Reynolds Number

def calculate_Re(velocity,diameter,density,viscosity):
    reynold_number = (velocity*diameter*density)/viscosity
    return reynold_number

The calculate_Re function takes four parameters: velocity, diameter, density, and viscosity. It calculates the Reynolds number using the formula (velocity * diameter * density) / viscosity and returns the result.

Classifying the Flow Type

def classify_flow(reynold_number):
    if reynold_number < 2300:
        return "Laminar Flow"
    elif reynold_number < 4000:
        return "Transitional Flow"
    else:
        return "Turbulent Flow"

The classify_flow function takes the Reynolds number as input and classifies the flow type based on the following criteria:

• If the Reynolds number is less than 2300, the flow is classified as “Laminar Flow”.
• If the Reynolds number is between 2300 and 4000 (exclusive), the flow is classified as “Transitional Flow”.
• If the Reynolds number is greater than or equal to 4000, the flow is classified as “Turbulent Flow”.

Calculating Head Loss

def calculate_headloss(diameter,length,velocity,density,viscosity):
    reynold_number = calculate_Re(velocity,diameter,density,viscosity)
    if reynold_number < 2300:
        friction_factor = 64/reynold_number
    else:
        friction_factor = 0.3164/(reynold_number**0.25)
    head_loss = (friction_factor*length*velocity**2)/(2*diameter*9.81)
    return head_loss

The calculate_headloss function takes five parameters: diameter, length, velocity, density, and viscosity. It first calculates the Reynolds number using the calculate_Re function.

Based on the Reynolds number, it determines the friction factor:

• If the Reynolds number is less than 2300, the friction factor is calculated as 64/reynold_number.
• If the Reynolds number is greater than or equal to 2300, the friction factor is calculated as 0.3164/(reynold_number**0.25).

Finally, it calculates the head loss using the Darcy-Weisbach equation: (friction_factor * length * velocity**2) / (2 * diameter * 9.81) and returns the result.

Processing Multiple Pipes

pipes = [
    {"diameter":0.5,"length":100},
    {"diameter":0.3,"length":150},
    {"diameter":0.4,"length":200},
]

def process_pipes(pipes,velocity,density,viscosity):
    results = []
    for pipe in pipes:
        try:
            diameter = pipe["diameter"]
            length=pipe["length"]
            head_loss = calculate_headloss(diameter,length,velocity,density,viscosity)
            results.append({
                "diameter": diameter,
                "length": length,
                "head_loss": head_loss
            })
        except KeyError as e:
            print(f"Missing key in pipe data: {e}")
        except Exception as e:
            print(f"An error occured: {e}")
    return results

The pipes list contains dictionaries representing different pipes with their respective diameters and lengths.

The process_pipes function takes four parameters: pipes, velocity, density, and viscosity. It iterates through each pipe in the pipes list and calculates the head loss using the calculate_headloss function. The results are stored in a dictionary and appended to the results list.

If a KeyError occurs (e.g., if a pipe dictionary is missing a key), an error message is printed. If any other exception occurs, a generic error message is printed.

Finally, the process_pipes function returns the results list containing the head loss for each pipe.

Executing the Code

reynolds_number = calculate_Re(velocity,pipe_diameter,fluid_density,fluid_viscosity)
flow_type = classify_flow(reynolds_number)
print("Reynolds Number:", reynolds_number)
print("Flow Type:",flow_type)

head_loss = calculate_headloss(pipe_diameter,pipe_length,velocity,fluid_density,fluid_viscosity)
print("Head Loss:", head_loss,"m")

pipe_results = process_pipes(pipes,velocity,fluid_density,fluid_viscosity)
print("\nResults for Multiple pipes:")
for results in pipe_results:
    print(results)

The code calculates the Reynolds number and classifies the flow type for the single pipe defined by the variables pipe_diameter, pipe_length, fluid_density, fluid_viscosity, and velocity.

It then calculates the head loss for the single pipe using the calculate_headloss function and prints the result.

Finally, it processes the multiple pipes defined in the pipes list using the process_pipes function and prints the results for each pipe.

Remember, this code assumes that you have a basic understanding of Python programming and fluid mechanics concepts.