Project Description

liquid fuel Combustion processes have been at the core of energy production and propulsion systems for over a century, providing the necessary thrust and power for a wide range of applications. Among the various types of fuels, liquid ethanol (C2H5OH) has gained attention as a renewable and cleaner-burning alternative to fossil fuels. When paired with an oxidizer such as nitrous oxide (N2O), ethanol can undergo a vigorous combustion reaction, releasing energy that can be harnessed for various industrial and technological purposes.

The geometry is designed using Spaceclaim software. The combustion chamber has 6000mm diameter with a fuel nozzle in the center. The model is then divided into elements in ANSYS Meshing software. In total, 769000 elements are generated.

Methodology

In order to model the fuel liquid droplets, two-way DPM module is used. Although the continuous phase is solved in steady mode, the discrete phase is tracked unsteadily. Moreover, the Standard K-epsilon turbulence model is utilized to predict flow behavior. Also, the Species Transport regarding the volumetric reaction and Eddy dissipation turbulent-chemistry interaction model is employed to simulate the combustion of ethanol and nitrous oxide.

Results

The simulation is performed in two major steps. Firstly, the continuous phase were solved. The velocity and pressure distribution reaches its steady condition after a while. Thus, the chamber average temperature reaches 320K and it is filled with nitrous oxide. It is time to start injection of fuel which is ethanol. The injection temperature is 273.15K and it injects 0.5mm fuel droplets into the chamber. The fuel temperature increases over time until it reaches its devolitization temperature. Thus, ethanol gas releases and get the chance to mix with oxidizer (N2o) and react. As a result, the temperature increases dramatically up to 460K (in average) and some products are produced based on the below reaction:

3C2h5oh + 2N2o  ===> 3Co2 + 4H2o + 2N2