0
Discussion

Discussion: “Numerical Study of Unsteady Jeffery Fluid Flow With Magnetic Field Effect and Variable Fluid Properties” (Mabood, F., Abdel-Rahman, R. G., and Lorenzini, G., 2016, ASME J. Therm. Sci. Eng. Appl., 8(4), p. 041003) OPEN ACCESS

[+] Author and Article Information
Asterios Pantokratoras

School of Engineering,
Democritus University of Thrace,
Xanthi 67100, Greece
e-mail: apantokr@civil.duth.gr

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF THERMAL SCIENCE AND ENGINEERING APPLICATIONS. Manuscript received October 28, 2016; final manuscript received December 23, 2016; published online April 12, 2017. Assoc. Editor: Giulio Lorenzini.

J. Thermal Sci. Eng. Appl 9(4), 045501 (Apr 12, 2017) (1 page) Paper No: TSEA-16-1308; doi: 10.1115/1.4036013 History: Received October 28, 2016; Revised December 23, 2016
FIGURES IN THIS ARTICLE

In the above paper, the energy equation (see Eq. (3) in Ref. [1]) is as follows: Display Formula

(1)Tt+uTx+vTy=1ρcpy(κTy)+Φρcp

where T is the fluid temperature, t is the time, u and v are the velocity components in the x and y directions, respectively, ρ is the fluid density, cp is the specific heat, κ is the thermal conductivity, and Φ is the heat source.

The units of temperature are

[T]=Kelvin(temperature)

The units of time are

[t]=sec(time)

Therefore, the units of (Φ/ρcp) are Ks1 in order that this term is compatible with the other terms in Eq. (1).

The units of specific heat are

[cp]=K1(Kelvin1)m2(length2)sec2(time2)

The units of density are

[ρ]=kg(mass)m3(length3)

Therefore, the units of Φ are Display Formula

(2)[Φ]=kg(mass)m1(length1)sec3(time3)

The heat source Φ is given by the following equation (see p. 2 in Ref. [1]): Display Formula

(3)Φ=κρus(x,t)μxQ0[TT]

where κ is the ambient thermal conductivity, us(x,t) is the suction velocity, and μ is the ambient dynamic viscosity. The units of thermal conductivity are

[κ]=kg(mass)K1(Kelvin1)m(length)sec3(time3)

The units of velocity are

[us(x,t)]=m(length)sec1(time1)

The units of dynamic viscosity are

[μ]=kg(mass)m1(length1)sec1(time1)

From Eqs. (2) and (3), it is found that the quantity Q0 is dimensionless. The heat source parameter is (see p. 3 in Ref. [1])

γ=Q0μρcpκ

and its units are

[γ]=kg1(mass1)K2(Kelvin2)m1(length1)sec4(time4)

This means the heat source parameter γ is dimensional and not dimensionless as the authors claim. Taking into account that the heat source parameter is one of the basic parameters, the results presented by Mabood et al. [1] are doubtful.

References

Mabood, F. , Abdel-Rahman, R. G. , and Lorenzini, G. , 2016, “ Numerical Study of Unsteady Jeffery Fluid Flow With Magnetic Field Effect and Variable Fluid Properties,” ASME J. Therm. Sci. Eng. Appl., 8(4), p. 041003. [CrossRef]
Copyright © 2017 by ASME
View article in PDF format.

References

Mabood, F. , Abdel-Rahman, R. G. , and Lorenzini, G. , 2016, “ Numerical Study of Unsteady Jeffery Fluid Flow With Magnetic Field Effect and Variable Fluid Properties,” ASME J. Therm. Sci. Eng. Appl., 8(4), p. 041003. [CrossRef]

Figures

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In