DESCRIPTION

Technical Description

The total pressure in a steady flow is constant. The sum of the static and dynamic pressures gives the total pressure. A change in the cross-section of the flow channel causes the flow velocity to vary inversely proportional to the cross-sectional area. These physical laws are fundamentals of fluid mechanics education.

The HM 225.03 experimental unit – used in the aerodynamics trainer HM 225 – allows the measurement of the total pressure and the static pressure.

A model is placed in the measuring section, which uses lateral bodies to produce a Venturi-shaped cross-sectional profile of the flow.

At the centre of the flow channel there is a Pitotstatic tube. The Pitotstatic tube has an opening opposite to the flow direction to measure the total pressure. The static pressure is measured through lateral inlet openings. Both pressures are read from the tube manometers in HM 225. The dynamic pressure is the difference between both measured values. 

In order to illustrate pressure and velocity distribution, measurements can be taken at different cross-sectional areas by moving the Pitotstatic tube in the flow direction.

The experimental unit is attached to the HM 225 trainer, simply and precisely with quick release fasteners.

The well-structured instructional material sets out the fundamentals and provides a step-by-step guide through the experiments.

Learning Objectives / Experiments

- investigation of the continuity equation and Bernoulli's principle
- determination of the dynamic pressure from the measurement data via Bernoulli's principle
- calculation of the flow velocity from the measurement data using Bernoulli's equation
- pressure and velocity distribution