Skip to main content
Log in

Analytical solution for the problem of maximum exit velocity under Coulomb friction in gravity flow discharge chutes

  • Original
  • Published:
Archive of Applied Mechanics Aims and scope Submit manuscript

Abstract

In this paper, an analytical solution for the problem of finding profiles of gravity flow discharge chutes required to achieve maximum exit velocity under Coulomb friction is obtained by application of variational calculus. The model of a particle which moves down a rough curve in a uniform gravitational field is used to obtain a solution of the problem for various boundary conditions. The projection sign of the normal reaction force of the rough curve onto the normal to the curve and the restriction requiring that the tangential acceleration be non-negative are introduced as the additional constraints in the form of inequalities. These inequalities are transformed into equalities by introducing new state variables. Although this is fundamentally a constrained variational problem, by further introducing a new functional with an expanded set of unknown functions, it is transformed into an unconstrained problem where broken extremals appear. The obtained equations of the chute profiles contain a certain number of unknown constants which are determined from a corresponding system of nonlinear algebraic equations. The obtained results are compared with the known results from the literature.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

Abbreviations

m :

Mass of the particle

\({\overrightarrow{v}}\) :

Velocity of the particle

\({\overrightarrow{a}}\) :

Acceleration of the particle

\({\overrightarrow{t}}\) :

Unit vector of the tangent

\({\overrightarrow{u}}\) :

Unit vector

v :

Projection of \({\overrightarrow{v}}\) onto \({\overrightarrow{t}}\)

μ :

Coefficient of friction

g :

Acceleration of gravity

\({\overrightarrow{N}}\) :

Normal component of the constraint reaction force

\({\overrightarrow{F}_{\mu}}\) :

Coulomb friction force

\({\varphi}\) :

Slope angle of the tangent

\({\dot{w}_{i}\,(i=1,2)}\) :

Slack variables

λ i  (i = 1, . . . , 5):

Lagrange multipliers

J :

Functional

F :

Integrand of the functional

Δ:

Noncontemporaneous variation

||:

Absolute value

References

  1. Charlton W., Roberts A.W.: Chute profile for maximum exit velocity in gravity flow of granular material. J. Agr. Eng. Res. 15, 292–294 (1970)

    Article  Google Scholar 

  2. Charlton W., Chiarella C., Roberts A.W.: Gravity flow of granular materials in chutes: optimizing flow properties. J. Agr. Eng. Res. 20, 39–45 (1975)

    Article  Google Scholar 

  3. Čović V., Vesković M.: Brachistochrone on a surface with Coulomb friction. Int. J. Nonlinear Mech. 43, 437–450 (2008)

    Article  Google Scholar 

  4. Čović V., Vesković M.: Brachistochronic motion of a multibody system with Coulomb friction. Eur. J. Mech. A Solid 28, 882–890 (2009)

    Article  MATH  Google Scholar 

  5. Elsgolc L.E.: Calculus of Variations. Pergamon Press, Oxford (1963)

    Google Scholar 

  6. Gelfand I.M., Fomin S.V.: Calculus of Variations. Prentice Hall, Englewood Cliffs (1964)

    Google Scholar 

  7. Gregory J., Lin C.: An unconstrained calculus of variations formulation for generalized optimal control problems and for the constrained problem of Bolza. J. Math. Anal. Appl. 187, 826–841 (1994)

    Article  MATH  MathSciNet  Google Scholar 

  8. Papastavridis J.G.: On a Lagrangean action based kinetic instability theorem of Kelvin and Tait. Int. J. Eng. Sci. 24, 1–17 (1986)

    Article  MATH  MathSciNet  Google Scholar 

  9. Parbery R.D.: Optimization of gravity flow discharge chutes for maximum exit velocity under Coulomb friction. Eng. Opt. 10, 297–307 (1987)

    Article  Google Scholar 

  10. Roberts A.W.: An investigation of the gravity flow of noncohesive granular materials through discharge chutes. Trans. ASME J. Eng. Ind. 91(Series B), 373–381 (1969)

    Google Scholar 

  11. Roberts A.W.: Chute performance and design for rapid flow conditions. Chem. Eng. Technol. 26, 163–170 (2003)

    Article  Google Scholar 

  12. Šalinić S.: Contribution to the brachistochrone problem with Coulomb friction. Acta Mech. 208, 97–115 (2009)

    Article  MATH  Google Scholar 

  13. Valentine F.A.: The Problem of Lagrange with Differential Inequalities as Added Side Conditions. Contributions to the Calculus of Variations, 1933–1937, pp. 407–448. University of Chicago Press, Chicago (1937)

    Google Scholar 

  14. Vuković, J.: On the determination of the constraints for the motion with the minimal loss of mechanical energy. In: Proceedings of the General Mechanics Symposium, Novi Sad, pp. 31–38 (in Serbian) (1994)

  15. Wensrich C.M.: Evolutionary solutions to the brachistochrone problem with Coulomb friction. Mech. Res. Commun. 31, 151–159 (2004)

    Article  MATH  Google Scholar 

  16. Wensrich C.M.: Evolutionary optimisation in chute design. Powder Technol. 138, 118–123 (2003)

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Slaviša Šalinić.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Šalinić, S. Analytical solution for the problem of maximum exit velocity under Coulomb friction in gravity flow discharge chutes. Arch Appl Mech 80, 1149–1161 (2010). https://doi.org/10.1007/s00419-010-0432-9

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00419-010-0432-9

Keywords

Navigation