Applications of Fluid Dynamics

Module aims

To explore a number of applications of fluid dynamics to areas within and beyond aeronautics, in fields such as convective heat and mass transfer, wind energy, bio-fluid mechanics, and road vehicle aerodynamics. At the same time the course aims to deepen the understanding of the physics and governing equations of fluid dynamics.

Specifically in the four parts of the course students will:

(i) obtain an understanding of the flow features around road vehicles, how this generates aerodynamic forces and affects vehicle performance;

(ii) learn how to apply fluid mechanics to describe the mechanics of flow in the human respiratory and cardiovascular systems;

(iii) gain some basic knowledge of the physical principles of operation of wind turbines and a good understanding of methods for their analysis and design; and

(iv) understand the way in which fluid mechanics may be combined with thermodynamics to model the transport of heat and mass.

Learning outcomes

Students would be able to:

• Describe the main features of the flow around a road vehicle, and provide an overview of how the aerodynamic forces arise.

• Explain how the aerodynamic forces are affected by vehicle shape and motion. 

• Analyse aerodynamic drag and relate to the features of both passenger and heavy road vehicles.

• Give an overview of testing and computational methods and to understand the need for designers to make trade-offs with other factors.

• Know and describe the essential characteristics and components of the cardiovascular and respiratory systems.

• Apply dimensional analysis to derive key parameters describing physiological flows.

• Relate simple models of pulse propagation in arteries to the dynamics of a compressible fluid.

• Construct appropriate models to describe transport and exchange process, including defining equations, boundary conditions and deriving solutions in simple cases.    

• Know the various types of wind turbines and assess their aerodynamic performance. 

• Predict how much power can be extracted from the wind using the actuator disk theory.

• Analyse the performance of HAWT and VAWT using the blade-element momentum theory.

• Understand the diffusive nature of heat conduction and how this will lead to convection at a fluid – solid boundary for which there is a temperature gradient present.

• Learn how to formulate and use the boundary layer equations for forced convection.

• Realise that the transfer of heat and mass is analogous and learn to exploit this analogy.

• Understand the relative importance of free and forced convection and in particular when one may be neglected for the other.

• Appreciate the important role that boundary conditions play in all heat and mass transfer problems.

Module syllabus

• Introduction to road vehicle aerodynamics. Review of bluff-body aerodynamics: aerodynamic forces; pressure-drag versus skin friction drag; types of flow separation. Factors affecting road vehicle aerodynamics: the ground effect; 3-D effects; rotating wheels, natural wind. Analysing aerodynamic drag. Aerodynamic drag of passenger cars and heavy vehicles. Testing and computational techniques. Methods for reducing drag. An automobile manufacturer perspective.
• Bio-fluid mechanics. Nature and composition of blood and of respired air; length and time scales; characteristics of basic components and processes. Dimensional analysis (Womersley & other parameters); Brownian motion and diffusion; particle transport; diffusion equation. Model flows; convective transport; exchange processes; equations and appropriate boundary conditions. Lumped parameter models for cardiovascular and respiratory systems. Applications & illustrations: flow measurement techniques, application of computational methods
• Aerodynamics of wind turbines. Introduction: Extracting energy from the wind; wind energy landscape; the atmospheric boundary layer; typology of wind turbines; drag versus lift devices. Horizontal-axis wind turbines (HAWT): nomenclature; evolution of HAWT; actuator-disk theory and Betz limit; blade-element momentum (BEM) theory; blade tip corrections. Vertical-axis wind turbines (VAWT): nomenclature; actuator-disk theory; BEM theory; HAWT vs VAWT.
• Mass and heat transport. A reminder of the modes of heat transfer; derivation of the hear diffusion equation; how boundary layer approximations may be used to understand forced convection; the similarity between the equations for heat and mass transfer and how various analogies may be made; solve for simple problems such as the flow over a heated flat plate; understand how heat/mass transfer from bluff bodies occurs; understand the relative importance of free/forced convection; solve for simple free convective flows such as that over a vertical heated plate; the importance of understanding free convection within an enclosure
 
 

Pre-requisites

AE2-201 Aerodynamics

Teaching methods

 lectures, tutorials.

Assessments

Examined Assessment
2.5 hour written closed-book examination  in January (100%)
Non-Examined Assessment
1 x Progress test (peer marked)

Reading list

Supplementary