Hydraulics does involve fluids, and has some fluid dynamics computationals related, but is not fluid dynamics.
Hydraulics Definition
'Study of liquids at rest and in motion, specially under pressure, and application of that knowledge in design and control of machines. In comparison, pneumatics is concerned with gases and their behavior under pressure.'
From:
http://www.businessdictionary.com/de...ydraulics.html
Hydraulics
'The branch of engineering that focuses on the practical problems of collecting, storing, measuring, transporting, controlling, and using water and other liquids. It differs from fluid mechanics, which is more theoretical and includes the study of gases as well as liquids; and from hydrology, which is the study of the properties, distribution, and circulation of the Earth's water.'
From:
http://www.answers.com/topic/hydraulics
Read more:
http://www.answers.com/topic/hydraulics#ixzz1Lp7psv8g
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Definition of Fluid Dynamics:
'Fluid dynamics is the study of fluids (liquids and gases) in motion, and the effect of the fluid motion on fluid boundaries, such as solid containers or other fluids. Fluid dynamics is a branch of fluid mechanics, and has a number of subdisciplines, including aerodynamics (the study of gases in motion) and hydrodynamics (liquids in motion). These fields are used in such wide-ranging fields as calculating forces and moments on aircraft, the mass flow of petroleum through pipelines, prediction of weather patterns, and even traffic engineering'
http://www.wordiq.com/definition/Fluid_dynamics
Since you are confused between Fluid Dynamics and Hydraulics, perhaps you should request a refund of the cost of your engineering degree, it did not help you much.