Julio Mendez

By Frederick Ferguson, Julio Mendez and David Dodoo-Amoo

Computational Fluid Dynamics (CFD) solutions have played an important role in the design and evaluation of complex problems where analytical solutions are not available. Among many practical applications, hypersonic flows have been an area of intense research because of the important challenges found in this flow regime. The numerical study conducted herein, focuses on solving the hypersonic flat plate problem under realistic conditions, at high Reynolds and Mach numbers. The numerical scheme implemented in this study solves the two-dimensional unsteady Navier Stokes Equations, using a novel technique called Integro-Differential Scheme (IDS) that combines the traditional finite volume and the finite difference methods. Moreover, this scheme is built on the premise of reducing the numerical errors through the implementation of a consistent averaging procedure. Unlike other numerical approaches, where free molecular effects are considered, this study enforces no-slip and fixed temperature as boundary conditions. The IDS approach accurately predicted the physics in the vicinity of the hypersonic leading edge at such realistic conditions. Even though there are slight discrepancies between the numerical solution and the available experimental data, the IDS solution revealed some interesting details about the flow field that was previously undiscovered.

Part of the book: Recent Trends in Computational Science and Engineering

By Mookesh Dhanasar, Frederick Ferguson and Julio Mendez

It can be argued that at the heart of functional hypersonic vehicle is its engine. Key to a functionally efficient scramjet engine lies in the design of its flow-path. The flow-path is made up of the following sections: (1) the forebody inlet; (2) the isolator, (3) the combustor, and (4) the nozzle. This chapter focuses on the design of the forebody inlet and the isolator sections of a scramjet engine. In this framework, key to a functionally efficient scramjet engine lies in the design of its flow-path. This flow-path design must consider a complex flow-field physics and the interaction of physical surfaces with this complex flow-field. Many attempts to design efficient scramjet flow-paths have met with some measured degree of success. This research uses a ?inverse design? approach, which is similar to Darwin?s theory of evolution, where an organism adopts to survive in its environment; the scramjet flow-path will be carved/extracted from the operational environment. The objective is to naturally and organically capture, process and direct the flow from the environment; thus preparing it for the combustion process. This approach uses the ideal 2-D oblique shock relations, coupled with Nonweiler?s caret waverider theory and streamline marching techniques.

Part of the book: Hypersonic Vehicles