Volume force

A volume force is a force that acts on the entire interior of a defined volume of a body. This distinguishes them from surface forces that act on (partial) surfaces of the body. Volume forces are caused by fields (e.g. gravitational acceleration, magnetism), which is why they are also called field forces .

The unit of measurement of a volume force in this sense is the Newton . Examples of such a volume force are weight , (d'Alembert's) inertial force or the Coulomb force .

Since the size of the force depends on the size of the volume, volume forces in applications in technical mechanics are often related to the volume. When the volume approaches zero, the local (specific) volume force is obtained with the unit . Such a procedure is particularly useful in fluid mechanics , where the volume force is part of the Navier-Stokes equations and, together with surface tension, describes the influence of external forces. ${\ displaystyle f}$ ${\ displaystyle {\ frac {\ mathrm {N}} {\ mathrm {m} ^ {3}}}}$

A volume force in this sense, i.e. with the unit force per volume unit, is a volume force density , an example is the weight .

literature

Batchelor, GK: An introduction to fluid mechanics, Cambridge University Press. ISBN 0-521-66396-2

Individual evidence

↑ ^a ^b ^c Werner Skolaut: Mechanical engineering: A textbook for the entire bachelor's degree . Springer-Verlag, August 13, 2018, ISBN 978-3-662-55882-9 , p. 698.
^ Alfred Böge: Technical Mechanics . Vieweg + Teubner, 2011, ISBN 978-3-8348-1355-8 ( limited preview in Google book search).
^ Gross, Dietmar; Hauger, Werner; Quick, Walter; Wriggers, Peter: Technical Mechanics . Springer Vieweg, Berlin, Heidelberg, 2018, ISBN 978-3-662-55694-8 , doi : 10.1007 / 978-3-662-55694-8 .
^ Schramm, Karl-Heinz: On the theory of the speed of sound in metals . In: Annals of Physics . tape 452 , no. 4-5 . Wiley Online Library, 1956, pp. 242-248 .

[Skolaut-1] Werner Skolaut: Mechanical engineering: A textbook for the entire bachelor's degree . Springer-Verlag, August 13, 2018, ISBN 978-3-662-55882-9 , p. 698.

[2] Alfred Böge: Technical Mechanics . Vieweg + Teubner, 2011, ISBN 978-3-8348-1355-8 ( limited preview in Google book search).

[3] Gross, Dietmar; Hauger, Werner; Quick, Walter; Wriggers, Peter: Technical Mechanics . Springer Vieweg, Berlin, Heidelberg, 2018, ISBN 978-3-662-55694-8 , doi : 10.1007 / 978-3-662-55694-8 .

[4] Schramm, Karl-Heinz: On the theory of the speed of sound in metals . In: Annals of Physics . tape 452 , no. 4-5 . Wiley Online Library, 1956, pp. 242-248 .