Omar Lopez Mejia

Universidad de Los Andes Colombia

Omar Dario Lopez Mejia, PhD, is an associate professor at the Department of Mechanical Engineering at the Universidad de los Andes in Bogota, Colombia. Prof. Lopez obtained his PhD degree in Mechanical Engineering from the University of Texas in Austin, USA, with specialization in thermal-fluid systems. His area of expertise is related to the simulation of external flows at moderate and high Reynolds number, including the simulation of the flow around MAVs, both fixed-wing and with rotors. Specifically, Prof. Lopez is interested in developing computational frameworks in which unsteady fluid dynamics simulation, structure interaction (RBD or flexible), and energy efficiency and control (including flow control) are highly coupled.

1books edited

1chapters authored

Latest work with IntechOpen by Omar Lopez Mejia

Few years ago, the topic of aerial robots was exclusively related to the robotics community, so a great number of books about the dynamics and control of aerial robots and UAVs have been written. As the control technology for UAVs advances, the great interaction that exists between other systems and elements that are as important as control such as aerodynamics, energy efficiency, acoustics, structural integrity, and applications, among others has become evident. Aerial Robots - Aerodynamics, Control, and Applications is an attempt to bring some of these topics related to UAVs together in just one book and to look at a selection of the most relevant problems of UAVs in a broader engineering perspective.

Go to the book

Aerial Robots

Edited by Omar Lopez Mejia

Chapters authored

Simulation of Axisymmetric Flows with Swirl in Vorticity- Stream Function Variables Using the Lattice Boltzmann Method

By Omar D. Lopez, Sergio Pedraza and Jose R. Toro

In the present work, a Lattice Boltzmann formulation in vorticity-stream function variables is proposed for axisymmetric flows with swirl. For this purpose, several source terms are proposed and implemented. Although containing velocity gradients, these sources are in the Lattice Boltzmann framework and fulfill the Euler and Navier-Stokes equations in their conservative form. The main characteristics of the proposed method are: First, the momentum equation is solved using a unified Lattice Boltzmann solver; second, the proposed sources are consistent with the nonviscous and viscous momentum equations; and third, the implemented method is second-order accurate in space. Numerical tests on the Taylor-Couette flow with finite aspect ratio of 3.8 and the lid-driven cylindrical cavity flow were carried out showing good agreement with numerical and experimental results found in the literature, evidencing the ability of the implemented method to solve axisymmetric flows with swirl. In the case of the lid-driven cylindrical cavity flow, the implemented method is able to correctly reproduce some qualitative characteristics of this flow such as the vortex breakdown close to the cavity axis at different Reynolds numbers and cavity aspect ratio.

Part of the book: Vortex Structures in Fluid Dynamic Problems

Omar Lopez Mejia

Latest work with IntechOpen by Omar Lopez Mejia

Aerial Robots

Chapters authored

Related collaborators

Ivan Salmerón

Ismael Pérez García

Tomoaki Watanabe

Gary Matthew Wysin

Sergio Pedraza

Jose R. Toro

Alejandro Aguilar

Jaime Hernández

Koji Nagata

Carlos B. da Silva