Heat transfer

Heat transfer

The heat transfer function is designed to simulate heat transfer between two objects. It takes the mass, temperature and specific heat capacity of the objects into account. *Note that later the list of factors being taken into account will be expanded.

Files related to the heat transfer function

The heat transfer function's main code is located in the src/modules/heat_transfer.rs source file. You can also find a unit test of the function at tests/heat_transfer_simulation_test.rs.

Usage of the heat transfer function

Parts of the heat transfer function

You can import these parts of the heat transfer function:

• simulate_heat_transfer — The function that does most of the work and processes the calculations
• HeatTransferResult — The part of the heat transfer function that gives you the ability to return specific values
• Object — The part of the heat transfer function that gives you the ability to create new objects

You can import all of those simply with:

use openphys::{simulate_heat_transfer, HeatTransferResult, Object};

Returnable values from the heat transfer function

These are the returnable values from the heat_transfer function:

• time_steps — The current amount of time steps, counting from 0
• total_time — The total amount of time elapsed since the start of the heat transfer
• total_heat_transferred — Total heat transferred between the two objects in Jules
• final_temp_of_obj1 — The final temperature of obj1
• final_temp_of_obj2 — The final temperature of obj2

Here's an example of how you could return one of these values:

println!("Total time: {:.2} seconds", result.total_time);

Creating new objects

You can create new objects with Object::new(mass, temperature, specific_heat_capacity).

• mass — The mass of the object in kilograms (kg)
• temperature — The temperature of the object in Kelvin (K)
• specific_heat_capacity — The amount of energy required to change the temperature of the object by 1K (J/kg*K)

An example of a new object is:

let mut obj1 = Object::new(1.0, 273.15, 4186.0); // 1kg of water at its freezing point

The variable is mutable because the simulate_heat_transfer function changes the temperature of the objects (obj1 in this case).

Setting up some other variables

Before we can begin using the simulate_heat_transfer function we need to specify some variables.

• time_step — The frequency we want the simulate_heat_transfer to update the temperature of an objects (1 time_step = 1 second) - adjust based on the accuracy you want, the recommended value is 0.1
• equilibrium_threshold — Once the difference between two objects' temperatures fall into this threshold, no further changes are made to the objects' temperatures, thus assuming balance between the two objects' temperatures - the temperature difference between the two objects doesn't have to be exactly 0, just low enough that they don't affect each other anymore - adjust based on the accuracy you want, the recommended value is 10^-6 but anything lower than 10^-2 will do

An example of specifying these two variable is:

let time_step = 0.1; // 0.1 seconds
let equilibrium_threshold = 1e-6; // 10^-6

Using the simulate_heat_transfer function

We can pass the two objects and the other variables we made into the simulate_heat_transfer as parameters like this: simulate_heat_transfer(&mut obj1, &mut obj2, time_step, equilibrium_threshold).

Here's an example of using the simulate_heat_transfer function with the variables we specified:

let result = simulate_heat_transfer(&mut obj1, &mut obj2, time_step, equilibrium_threshold);