Fluid Dynamics Module Quiz

The tendency of a fluid to resist flow, measured by its internal friction.

A property of a fluid that indicates how much its viscosity changes with temperature.

A high V.I. indicates that the oil's viscosity changes very little with temperature.

A low V.I. indicates that the oil's viscosity changes significantly with temperature.

The shaping of an object to reduce air resistance caused by viscosity.

The lines that represent the direction of air flow around an object.

Streamlining reduces air resistance, allowing for faster speeds and improved fuel efficiency.

A well-rounded front and a gradually tapered rear section are important for reducing air resistance in subsonic speeds.

The density of a solid or liquid changes with temperature. A standard temperature of 4°C is used when measuring the density of solids and liquids.

The density of a gas changes with both temperature and pressure. Gas density increases proportionally with pressure.

A comparison of the density of a substance to the density of a standard reference substance. For liquids and solids, water at 4°C is the standard. For gases, air at 0°C is the standard.

A device that measures the specific gravity of liquids. It consists of a weighted glass float in a larger tube.

Viscosity is affected by temperature and pressure. As the temperature of a liquid increases, its viscosity decreases. High pressure on a liquid increases its viscosity.

Fluids that are too thin (low viscosity) can cause rapid wear on moving parts. Fluids that are too thick (high viscosity) create high internal friction.

The term viscosity also applies to gases.

The ability of a fluid's molecules to be compacted or compressed, leading to an increase in density, and their ability to regain their original density.

A fluid that cannot be compressed and maintains a constant density throughout.

A fluid that can be compressed, changing its density.

The pressure exerted by the atmosphere due to its weight.

Pressure arising from the motion of an object through a fluid.

The combined pressure of static pressure and dynamic pressure.

An instrument used to measure fluid flow velocity by measuring the total pressure.

At low speeds, the compressibility of air is negligible for aircraft, meaning the aircraft's movement doesn't significantly affect air density.

A passageway in a duct system that widens, increasing its cross-sectional area.

A principle stating that the fluid's static pressure decreases when its velocity increases, with no energy gain or loss.

The reduction in fluid pressure that occurs when a fluid passes through a constricted section of a pipe.

A device designed to increase the velocity of a fluid by forcing it through a constricted section.

The pressure exerted by a stationary fluid, measured relative to a reference pressure.

The pressure resulting from the movement of a fluid.

The sum of static pressure and dynamic pressure.

The equation describing the relationship between static pressure, dynamic pressure, and total pressure in fluid flow.

The pressure related to the fluid's state, not its motion. In aircraft, it's the atmospheric pressure.

The pressure associated with a fluid's motion, calculated as half of the density times velocity squared.

The sum of static pressure and dynamic pressure. It's the total pressure exerted by a fluid.

A sealed capsule used for measuring dynamic pressure in aircraft.

A tube with a narrowing section in the middle. It is used to demonstrate Bernoulli's principle.

This principle states that as the speed of a fluid increases, its pressure decreases. This occurs while the total energy remains constant.

The potential energy of a fluid is related to its pressure, and kinetic energy is related to its motion.

Bernoulli's Principle allows for energy exchange within a fluid. Potential energy can be converted into kinetic energy and vice versa.

The Venturi effect is the reduction of fluid (air, liquid) pressure as the fluid speed increases through a narrowed area. This is observed when air flows through a venturi, where the velocity increases, and the pressure decreases at the throat, leading to a pressure difference between the wider and narrower sections.

Bernoulli's theorem states that as the speed of a fluid (liquid or gas) increases, its static pressure decreases, assuming the total energy of the fluid remains constant.