The future Colombian aerospace highway: contributions from fluid mechanics to the country's aeronautical development

Brayan Manuel Guerrero Martínez, Master's student in Engineering with Emphasis in Aerospace Engineering. Credit: researcher's courtesy.

Colombia's geographical location places it in the middle of a complex aeronautical scenario, since the high mountain ranges endanger aircraft operations and limit the connection with distant areas of the country. However, this characteristic offers and demands, in turn, the development of new devices adapted to the geographical complexity of the territory, in terms of aerospace potential. An investigation evaluates the behavior of a prototype in these scenarios and seeks to test a novel design that will contribute to the development of aircraft in the future. 

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A commitment to contribute to the aviation of tomorrow  

Regions such as the Pacific, the Eastern Plains and the Atlantic Coast, due to their topographic characteristics, make Colombia a country with a vast potential in aerospace matters. These regions, where wide flat extensions and mountainous formations predominate, are an ideal scenario to strengthen and increase air transportation for regions of difficult access, so that the use of helicopters, airplanes, drones and airships for commercial purposes and academic and technological research tasks can be possible. The development and subsequent implementation of this sector requires an infrastructure adapted to the characteristics of these territories, which poses a challenge for the design of elements that help to overcome these circumstances without implying a setback.   

Given this scenario, the Mechanical Engineer Brayan Manuel Guerrero Martinez decided to carry out a research project within the framework of the master's degree in engineering with Emphasis in Aerospace Engineering at the Universidad del Valle. This project, directed by professor and researcher Guillermo Andrés Jaramillo Pizarro PhD and director of the Impetus Indomitus Research Team of the School of Mechanical Engineering, seeks to contribute to the aerial interconnection of the country with its most rugged and remote regions. The idea of this project is to contribute to what is expected to be, according to Professor Jaramillo, the future Colombian aerospace highway linking the country.  

"From my area of knowledge I have focused on fluid mechanics, mainly in aerodynamics, which is the one that studies the interaction of air flows or other gases with solid bodies," says the researcher Guerrero Martinez. His research seeks to contribute to the development of devices that meet the needs and adapt to the Colombian geographical reality, through the creation of an experimental aerodynamic profile (which can be scaled up to become the wing of an airplane) whose characteristics allow aircraft a greater margin of maneuver in areas of high accident rate and contribute to the connection of areas of difficult access.   

Research: wind tunnel and test bed  

Structure of the wing profile used in the investigation, NACA 0018. The figures at the bottom show the blunt bodies tested. Credit: researcher's courtesy.

After the corresponding bibliographic review, which showed studies related to the evaluation of similar aeronautical devices whose results have been published since the 1970s, the researcher Brayan Manuel Guerrero Martínez carried out the experimentation of his prototype in two areas, typical of the praxis within fluid mechanics: one experimental, which shows the results against real conditions and tests, and another by means of computational fluid simulation (CFD), which allowed him to visualize more scenarios and obtain more robust information about the evaluated phenomenon.  The research used a section of an aircraft wing, known as the airfoil (the shape), a characteristic that is standardized for different aircraft shapes and types. In this case, a NACA 0018 airfoil was used.   

In the project, blunt bodies (one circular and one triangular) were added at the leading-edge points of the airfoil, that is, at the start or nose of the wing, which rotated to accelerate the air passing around the airfoil. This addition was intended to increase the lift force and aid in the aerodynamic performance of the airfoil as such.   

For the continuation of the process, it was necessary to build two experimental evaluation instruments. On the one hand, a wind tunnel, a construction made possible thanks to the joint work of Professor Jaramillo Pizarro and the members of the Impetus Indomitus Research Team, which allows controlled air flows for aerodynamic experiments. And on the other hand, a test bench, an instrument similar to a balance that contained load cells to record forces. This bench was designed to measure forces on two different axes: the one that lifts and allows bodies to fly, known as lift force, and the one that opposes the movement of objects, known as drag force.   

This bench was built by researcher Guerrero Martínez, as he progressed in his research.   

 The assembly process of the instruments was as follows: the airfoil together with the added blunt bodies was arranged under the bench, which was in turn coupled to the wind tunnel, so that the experimental forces could be measured by means of the load cells (Strain gauge) and collected through the test bench for further analysis. For the recording of such information the researcher built an electronic data acquisition system based on Arduino, taking advantage of its accessibility in the academic environment.  The evaluation was performed at different rotation speeds in the blunt bodies and different angles of attack (the position in which the wing is with respect to the air flow), due to its relevance when investigating aeronautical profiles.   

Aerodynamic balance (test bench) used to model the information, according to the different scenarios to which the wing prototype was subjected. Credit: researcher's courtesy.

The variables to be evaluated through this process had to do with the increase in percentage of lift and drag that the wing could have, the force registered by the device and the rotation speeds of the added blunt bodies.   

Two softwares were used for the simulation: Ansys, for commercial use, and Openfoam, for free use. They were used to demonstrate the behavior of the airstream lines once they encountered the device, how they crossed the airfoil and how the added bodies modified the airflow. In the CFD simulations, the Navier-Stokes equations, known for modeling the aerodynamic flow of bodies, were solved using the RANS (Reynolds Average Navier-Stokes) method and the K-ω SST turbulence model.   

The numerical results were compared with those obtained through the experimental process carried out with the wind tunnel and the test bench.  

Prototype behavior and air flow lines, analyzed through computational fluid simulation. Credit: researcher's courtesy.

 Research findings  

"Within the work we were able to demonstrate what is somehow mentioned in the literature, and that is that the addition of these blunt bodies helps to improve the lift and, therefore, the performance of an airfoil and subsequently of a wing," says researcher Brayan Manuel Guerrero Martinez. According to him, although the improvement for the triangular blunt body was only 4% in terms of lift force, a superior improvement was obtained for the circular blunt body, with about 20% more lift force.   

On the other hand, the research showed an improvement in the operability of the airfoil at high angles of attack, which contributes to a better operation of aircraft in the future in areas with high accident rates due to their mountainous characteristics.  

"These results continue to demonstrate the benefits that, in the future, these technologies may have. This continues to be promising for the development of aeronautical profiles in Colombia," says researcher Guerrero Martínez.  

Regarding the contribution of this research work to the future of the Colombian aerospace highway, the researcher believes that there will be more and more room for this type of development, taking into account the boom in aeronautical devices, such as drones, so that these devices can be nourished by the advances made in this and future research.   

In this sense, Universidad del Valle is at the forefront of innovative bets in this field. "The University is already developing the tools to create aeronautical devices. At a regional level, these technologies can be applied to devices designed for Colombia", are his words.

If interested in being in touch with the Master's student or any further information about the investigation, please write the Faculty of Engineering Communications Office: comunicaingenieria@correounivalle.edu.co.