Längdhastighet

Längdhastighet, often translated as longitudinal velocity or axial velocity, refers to the component of an object's velocity that is parallel to its axis of rotation. This concept is particularly relevant in the study of rotating machinery, such as turbines, propellers, and centrifugal pumps, as well as in celestial mechanics concerning the rotation of planets and stars.

In simpler terms, imagine a spinning object. Its rotational velocity describes how fast it's turning around its center. Längdhastighet, however, focuses on the speed of points on the object moving in the direction of its rotational axis. For instance, in a turbine blade, points closer to the tip will have a higher tangential velocity than points near the hub, but their längdhastighet might be different depending on the design and how the fluid or material is flowing along the axis.

This velocity component is crucial for understanding fluid dynamics within rotating systems. It influences the pressure distribution and the overall efficiency of devices. In astrophysics, the längdhastighet of different parts of a rotating celestial body can indicate internal convection currents or the distribution of mass. Measuring or calculating längdhastighet helps engineers and scientists optimize performance, predict wear, and understand complex physical phenomena. It is distinct from tangential velocity, which is perpendicular to the axis of rotation.