Mechanical Engineering

Objects, vehicles, and organisms in fluids experience buoyancy, drag, and lift. Buoyancy is the upward force from the fluid’s weight. Drag is the resistive force that acts opposite motion. Lift is the force perpendicular to the direction of motion.

These forces matter in engineering and in the study of swimming and flying organisms. Predicting and measuring them helps explain how bodies move through a fluid medium. It also supports the design of vehicles that travel through liquids or gases.

Boat stability depends on hull shape and internal mass distribution. A stable vessel can self-right after it is rolled to one side by an outside force. Careful hull design helps seagoing vessels stay stable with a low draft, which is the submerged depth of the hull. That can improve maneuverability and reduce drag.

This experiment uses a model boat with an adjustable center of mass, which represents different cargo loadings. The boat is also modified for automated tracking of its roll angle.

Propulsion systems create thrust by speeding up a surrounding fluid or high-temperature combustion products. Aircraft, rockets, and ships all use this basic idea. When the fluid leaves at high velocity, conservation of momentum produces an effective force on the vehicle.

Thrust is often checked with static thrust tests. In these tests, the propulsion system is fixed to an instrumented mount, and the holding force on the mount is measured as thrust. This setup lets the system run while the...

This experiment measures pressure drop in pipe components used in internal flow systems. Friction from channel walls, fittings, and obstructions can turn fluid pressure into heat, which reduces the pressure available for flow.

A piping network is built with straight tubing, helical tube coils, and elbow fittings with sharp 90° bends. Pressure loss is measured across each component set with manometers, which show fluid pressure by the height of liquid in an open vertical column.

The measured...

Controlled heating followed by rapid cooling is a key step in many materials processing applications. This heat-treating process can make a material harder. That matters for cutting tools and for surfaces that must resist wear.

The rapid cooling stage is called quenching. It is often done by placing the material in a fluid bath, such as water or oil. Quenching heat transfer can happen by forced convection, when fast movement through the coolant drives heat transfer, or by free convection, when...

Hydraulic jumps show how fast open-channel water can suddenly slow down and rise. When water moves at high velocity along an open channel, the flow can become unstable. Small disturbances can make the upper surface jump to a higher level.

This abrupt rise is called a hydraulic jump. As the water level increases, the average flow velocity drops. The fast-moving water also loses kinetic energy, and that energy is dissipated as heat.

Engineers often build hydraulic jumps into large water works,...

Heat exchangers move thermal energy between two fluid streams and are common in energy systems. They appear in car radiators, refrigerator evaporators, and cooling towers in power plants. In each case, heat moves from one fluid to another, either directly or through a surface.

This experiment focuses on a water-to-water tube-in-tube heat exchanger. The setup is built and then tested with temperature and flow rate measurements. These measurements are used to find the heat transfer rate, or Q,...

Vapor compression refrigeration shows how refrigerators, freezers, air-conditioning systems, and heat pumps remove heat. It is the dominant refrigeration technology used in many everyday devices. In this cycle, cooling happens when refrigerant evaporates at low pressure. The absorbed thermal energy is then released to the surroundings when the refrigerant condenses at high pressure.

The compressor is the part that raises the working fluid from low pressure to high pressure. Mechanical work is...

Hot-wire anemometry measures fast changes in fluid flow with a thin heated wire. Its very short time response makes it useful for rapidly fluctuating motion, especially turbulent flows.

This experiment demonstrates how hot-wire anemometry is used in practice. It shows a method for tracking flow conditions when quick changes matter. The setup highlights why a hot-wire anemometer can capture details that slower sensors may miss.

Hot-wire anemometry is used to measure a turbulent jet and study its fast changes in speed. Turbulent flows have very high-frequency fluctuations, so they require instruments with a fast time response for proper measurement. A hot-wire anemometer has that short response time and can capture these rapid velocity changes.

A previously calibrated hot-wire probe is used to collect velocity data at different positions within the jet. These measurements show how the flow varies across the turbulent...

Hydrogen bubble flow around a circular cylinder shows how fluid moves past a bluff body. A bluff body is an object with a shape that causes separated flow over most of its surface. This is different from a streamlined body, such as an airfoil, which stays aligned with the stream and causes less flow separation.

Fluid motion can form complex patterns because its governing laws are non-linear. Scientists have studied these patterns for centuries. Computers and supercomputers can help predict...

A plane jet striking an inclined plate shows how fluid flow can exert force on a surface. The experiment focuses on how dynamic pressure changes into static pressure at the plate and how that change affects the load on the structure.

Pressure is measured along the plate to build a pressure distribution. The plate has small perforations called pressure taps, and these taps connect through hoses to a scanning valve. The scanning valve sends pressure from one tap at a time to a diaphragm pressure...

This experiment examines steady, incompressible flow in a short pipe with a gate valve. It uses the energy conservation equation to track how pressure and flow change through the system.

The gate valve is gradually closed, and its effect on the flow conditions is measured. The setup shows how energy dissipation helps a valve restrict flow. It also links the pipe system to the fan that drives the flow by comparing the system curve with the fan’s characteristic curve.

The same pressure-based...

Mass conservation can be used to calibrate a smooth contraction as a flowmeter. The experiment uses a control volume, or CV, formulation. A control volume is a simplified region used to study the macroscopic effect of flow on an engineering system.

This approach focuses on the main mass exchange in the system rather than the detailed flow pattern. It is a complementary method to differential analysis, which looks at the flow in more detail. In design work, the CV method can give an engineer an...

A plane jet striking a flat plate creates a force that can be estimated from changes in linear momentum. This experiment uses a control volume formulation to study that force at different angles. A control volume is an imaginary closed surface that surrounds the flow region and helps simplify the analysis.

The control volume approach focuses on the macroscopic effect of flow on an engineering system. It does not try to describe every detail of the fluid motion. Instead, it identifies the main...