**2. Heat transfer analysis**

Thermal energy analysis is a complex task that usually requires the use of large theoretical equations and mathematical models that can predict the behavior of a certain system. It is not easy to simplify natural or forced convection, phase change phenomena, or radiation heat transfer, considering their interactions with other parts of the system under study. Therefore, most of the engineers and researchers in the thermal field turn to computational models and test benches that help them understand all these processes [9].

#### **2.1 Computational simulations**

A very common approach to heat transfer study is to develop a computational model making several assumptions prior to the simulations. These models use thermodynamic equations and energy balances to represent what we can expect to happen in real conditions. These computational tools are really useful since they allow us to perform tons of simulations and analyze many cases in a cost-effective manner. You can use them to optimize a certain design and be sure that it will work properly once it has been built. Besides, by using these models a sensitive analysis can be performed to check which parameter is affecting more to the results of the system. There are many ways to develop these models, using different solving techniques. It is essential to understand the heat transfer phenomena you want to study and then check for the best method to model it.

### **2.2 Experimental analysis**

Another approach to study heat transfer problems is to design and build an experimental test bench. Sometimes it is so difficult to theoretically model a thermal energy system that it is more convenient to analyze the problem experimentally. Therefore, an experimental rig is employed to obtain useful results of the cases under study. Often, all these rigs allow the researcher to modify the boundary conditions affecting the system, so the problem can be tested under different circumstances. These test benches are also useful to validate the computational models and check if they can properly predict the behavior of the system.
