THE NEW ENGINEERING

 

Dear colleague,

 

The following short narrative critically appraises conventional engineering science, describes the new engineering science that should replace it, and demonstrates the solution of several practical problems using the new engineering.  The particular advantages of the new engineering are that it is easier to learn because there are fewer parameters, and it greatly simplifies the solution of nonlinear problems by reducing the number of variables.

 

The rest of this website concerns my papers, letters, books, presentations, patents, and narratives that relate how I have promoted the new engineering, and how the promotion has been received.

 

Eugene F. Adiutori

 

 

Why parameter symbols are dimensionless in the new engineering.

In the new engineering, parameter symbols are dimensionless because engineering data describe how the numerical values of parameters are related.  

 

For example, Hooke’s data do not indicate that “stress is proportional to strain”.  Hooke’s data indicate that “the numerical value of stress is proportional to the numerical value of strain”.  Therefore the correct symbolic expression of Hooke’s law is s a e in which s and e are dimensionless

 

Data indicate that “the numerical value of stress is always a function of the numerical value of strain”.  This statement is a law because it describes behavior, and is always obeyed.  The correct symbolic expression of this law is s = f{e} in which s and e are dimensionless.  This law replaces s = Ee, and makes it necessary to abandon E because E is defined by s = Ee.

 

Data indicate that “the numerical value of convective heat flux is always a function of the numerical value of temperature difference”.  This statement is a law because it describes behavior, and is always obeyed.  The correct symbolic expression of this law is q = f{DT} in which q and DT are dimensionless.  This law replaces q = hDT, and makes it necessary to abandon h because h is defined by q = hDT.

 

Data indicate that, in resistive electrical components, “the numerical value of electromotive force is always a function of the numerical value of electric current”.  This statement is a law because it describes behavior, and is always obeyed.  The correct symbolic expression of this law is V = f{I} in which V and I are dimensionless.  This law replaces V = IR, and makes it necessary to abandon R because R is defined by V = IR.

 

 

How dimensionless parameter symbols greatly improve engineering science.

Dimensionless parameter symbols result in a greatly improved engineering science by making it necessary to replace  laws such as s = Ee, q = hDT, and V = IR with laws such as s = f{e}, q = f{DT}, and V = f{I}, and to abandon parameters such as E, h, and R.  The improvements are:

 

·   It is much easier to learn engineering science because the abandonment of parameters such as E, h, and R reduces the number of concepts that must be understood and applied.

 

·   It is much easier to solve nonlinear problems because the abandonment of parameters such as E, h, and R reduces the number of variables in nonlinear problems.

 

·   All parametric equations are inherently dimensionless and dimensionally homogeneous.  Therefore all parametric equations are dimensionally acceptable. 

 

·   Engineering science is more rational because engineering data and engineering equations and engineering charts describe how the numerical values of parameters are related. 

 

 

How dimensionless parameters greatly simplify the solution of nonlinear problems.

Dimensionless parameters greatly simplify the solution of nonlinear problems by making it possible to abandon parameters such as h, E, and R.  These parameters are undesirable because they are variables in nonlinear problems. 

 

For example, q = hDT and h = q/DT are identical.   Therefore h and q/DT are identical and interchangeable.  If q is proportional to DT, q/DT (aka h) is a constant, and both q = hDT and q = f{DT} contain the two variables q and DT.  But if q is a nonlinear function of DT, q/DT (aka h) is a variable, and q = hDT contains the three variables q, DT, and q/DT (aka h), whereas q = f{DT} contains only the two variables q and DT.    

 

It is self-evident that any nonlinear problem that can be solved with the three variables q, DT, and q/DT (aka h) can also be solved with the two variables q and DT, and that the two variable solution is much simpler. 

 

And similarly for E and R.

 

 

Dimensional homogeneity in the new engineering.

In the new engineering, parameter symbols are dimensionless, and therefore all parametric equations are dimensionless and dimensionally homogeneous.  If an equation is quantitative, the dimension units that underlie parameter symbols must be specified in an accompanying nomenclature. 

 

 

The replacements for parameters such as q/DT (aka h), s/e (aka E), and V/I (aka R).

The only reason parameters such as h, E, and R are required in conventional engineering is because it is not possible to have a dimensionally homogeneous law in the form of a proportional equation unless the coefficient in the equation is the ratio of the two parameters in the equation.  For example, q = hDT is a law in the form of a proportional equation, and it is dimensionally homogeneous only because h is the ratio q/DT.  And similarly for E and R.

 

Because parameters such as h, E, and R are required only for the dimensional homogeneity of engineering laws, and because equations are inherently dimensionally homogeneous in the new engineering, parameters such as h, E, and R can be, and are, abandoned and not replaced.

 

 

The remainder of this narrative is a slightly modified form of several pages taken from my article in The Open Mechanical Engineering Journal, 2018, 12: 164-174.  The article can be downloaded without charge at https://www.benthamopen.com/tomej/.

 

Transformation from conventional engineering to the new engineering.

The transformation from conventional engineering to the new engineering is quite simple.  For example, to transform the subject of convective heat transfer to the new engineering:

 

·   Replace Eq. (1) with Eq. (2).

 

q = hDT                                                                                                                                (1)

 

q = f{DT}                                                                                                                             (2)

 

·   Recognize that parameter symbols represent numerical value, but not dimension.

 

·   Recognize that h and q/DT are identical and interchangeable.

 

·   In all equations that explicitly or implicitly include h, substitute q/DT for h and for kwall/twall, then separate q and DT. 

 

For example, the transformation of Eq. (3) results in Eq. (4), and the transformation of Eq. (5) results in Eq. (6).

 

U = 1/(1/h1 + twall/kwall+ 1/h2 )                                                                                                 (3)

 

DTtotal = DT1 + DTwall + DT2                                                                                                    (4)

 

Nu = a Reb Prc                                                                                                                         (5)

 

q = a(k/D)Reb PrcDT                                                                                                               (6)

 

In the new engineering, Eqs. (1), (3), and (5) are abandoned, and are replaced by Eqs. (2), (4), and 6).  And similarly for other branches of engineering.  Note that Eqs. (3) and (4) are identical, and that Eq. (4) is so simple it is intuitive, whereas Eq. (3) is far from intuitive.  It is much easier to learn how to solve problems using Eq. (4) rather than Eq. (3).  And any heat transfer problem that can be solved using Eq. (3) can also be solved using Eq. (4). 

 

If a heat transfer problem concerns proportional behavior, it is easily solved using either Eq. (3) or Eq. (4) because both equations contain only two variables.  However, if a heat transfer problem concerns moderately nonlinear behavior, the solution is quite simple if Eq. (4) is used, and considerably more difficult if Eq. (3) is used, as demonstrated by the problem in Table 1.  If a heat transfer problem concerns highly nonlinear behavior, the solution is quite simple if Eq. (4) is used, and virtually impossible if Eq. (3) is used.

 

The solution of proportional and moderately nonlinear heat transfer problems using conventional engineering and the new engineering.

Table 1 describes the solution of a moderately nonlinear heat transfer problem that concerns heat transfer between two fluids separated by a flat wall.  The solution on the left side of Table 1 is based on conventional engineering.  The solution on the right side is based on the new engineering.  The solutions described in Table 1 are typical of problems in which the thermal behavior of boundary layers is described by equations (rather than charts). 

 

Note the following in Table 1:

 

·   The equations on the left side of Table 1 are identical to the equations on the right side.  They differ only in form. 

 

·   The equation on the left side of Line 6 is much more difficult to solve than the equation on the right side because it contains three unknowns (U, DT1, and DT2), whereas the equation on the right side contains one unknown (q).

 

·   The equation on the right side of Line 6 can be solved in about a minute using Excel and trial-and-error methodology.  It would take much longer than a minute to solve the equation on the left side, and the likelihood of error would be much greater.

 

·   If DT1 and DT2 were proportional to q—ie if h1 and h2 were constants—the equations on both sides of Line 6 would be simple to solve.  In other words, proportional problems are very simple to solve whether the solution is based on q = hDT or DT = f{q}.

 

·   The problem in Table 1 can be solved graphically if the solution is based on DT = f{q}  because the equation on the right side of Line 1 can be solved graphically.  The problem in Table 1 cannot be solved graphically if the solution is based on q = hDT because the equation on the left side of Line 1 cannot be solved graphically.  

 

 

                                                                  Table 1

 

                                      The solution of a moderately nonlinear

                            heat transfer problem based on q = hDT and DT = f{q}.

 

 

   Based on q = hDT.                                              Based on DT = f{q}.

 

U = 1/(1/h1 + t/k + 1/h2)                                DTtotal = DT1 + DTwall + DT2                     (1)

 

DTtotal = 320 – 200 = 120                               DTtotal = 320 – 200 = 120                          (2)

 

h1 = .40(DT1).33                                              DT1 = 1.99q.75                                            (3)

 

twall/kwall = .05                                                DTwall = .05q                                              (4)

 

h2 = .80(DT2).50                                              DT2 = 1.16q.667                                          (5)

 

U = 1/(1/.4(DT1).33 +.05 + 1/.8(DT2).50)         120 = 1.99q.75  + .05q + 1.16q.667              (6)

 

 

The solution of a highly nonlinear heat transfer problem using the new engineering.

If DT2{q} in Table 1 were so highly nonlinear that it included a region in which dq/dDT2 is negative, the relationship between q and DT2 would probably be described graphically in the form q vs DT2.  The problem could have more than one solution, and operation might be thermally unstable in the region in which dq/dDT2 is negative.  Such problems are solved quite simply if the solution is based on q = f{DT}, as demonstrated by the following:

 

·   Use the given information to plot qout vs (T2 + DT2{qout}).  Note that (T2 + DT2{qout) is the temperature of the interface that adjoins Fluid 2, and qout is the heat flux out of that interface.

 

·   On the same chart, use the given information to plot qin vs (T­1 - DT1 - DTwall).  Note that           (1 - DT1 - DTwall) is the temperature of the interface that adjoins Fluid 2, and qin is the heat flux into that interface.

 

·   At intersections of the two curves, the heat flux into the interface in Fluid 2 equals the heat flux out of that interface.  Therefore intersections are steady-state operating points provided operation at the intersection is thermally stable.

 

·   If an intersection is in a region in which dq/dDT2 is negative, operation may be thermally unstable.  To appraise thermal stability at the intersection, inspect the chart to determine whether a small perturbation at the intersection would shrink or grow.

 

·   If a small perturbation would shrink, operation at the intersection is thermally stable with respect to small perturbations.  (It may be thermally unstable with respect to large perturbations.) 

 

·   If a small perturbation would grow, operation at the intersection is thermally unstable.

 

o If the unstable intersection lies between two other intersections, inspection of the chart will indicate that the instability results in hysteresis.

 

o If there is only one intersection, inspection of the chart will indicate that the instability results in undamped oscillations in temperature and heat flux.

 

 

The solution of a highly nonlinear heat transfer problem using conventional engineering.

The solution of the highly nonlinear problem above is quite simple because the solution is   based on q = f{DT}.  If the solution is based on q = hDT, the chart of q vs DT2 is replaced           by a chart of h vs DT2, and the addition of the variable h adds so much complexity that it is virtually impossible to determine the correct and complete solution of the problem.  

 

 

The solution of stress/strain problems in the elastic region based on s = elastice and

on s = f{e}.

In the elastic region:

 

·   s = Eelastice is a proportional equation, and Eelastic is a dimensioned proportionality constant.

 

·   s = f{e} is the proportional equation s = ce, and c is a dimensionless proportionality constant.

 

·   c is numerically equal to Eelastic.  

 

Because both s = Eelastice and s = ce are proportional equations, and because c and Eelastic are numerically equal, the solution of elastic problems based on s = ce is identical to the solution based on s = Eelastice.   The only difference between the two solutions is that the symbols in one equation represent numerical value and dimension, whereas the symbols in the other equation represent numerical value but not dimension.

 

Why inelastic stress/strain problems are much simpler to solve if the solution is based

on s = f{e} rather than s = Esecante.

In the inelastic region, E is the variable Esecant.  Because s = Esecante contains three variables in the inelastic region whereas s = f{e} contains only two variables, inelastic problems are much simpler to solve if the solution is based on s = f{e}.

 

The following problem demonstrates that inelastic problems are much simpler to solve if solutions are based on s = f{e} rather than s = Esecante.

 

The solution of a stress/strain problem using s = Ee.

Determine the strain in the bar.

Given:

·   The stress in the bar is 45,000 kg/cm2.

 

·   Ebar = f{e} is described in Figure 1.

Analysis

The analysis based on s = Ebare is not difficult, but it is time-consuming, and there is a considerable likelihood of error.

 

 

Solve the above problem using s = f{e}.

Given:

·   The stress in the bar is 45,000 kg/cm2.

 

·   s = f{e} is described in Figure 2.

 

 

 

Analysis and solution:

Inspection of Figure 2 indicates that the strain in the bar may be .0015, .0036, or .0068.  The given information is not sufficient to determine a unique solution.

 

 

The purpose of the bar problem.

The purpose of the bar problem is to demonstrate that it is much easier to solve inelastic problems if E is not used in the solution.  If E is not used, the correct and complete solution of the bar problem requires less than ten seconds, and there is virtually no chance of error.  If E is used, the correct and complete solution requires much longer than ten seconds, and there is a considerable chance of error because the problem does not have a unique solution.

 

 

Why “stress/strain charts” are not charts of stress vs strain, and why “stress/strain

charts” are in precisely the form required in the new engineering.

Just as equations always describe how the numerical values of parameters are related, charts always describe how the numerical values of parameters are related. 

 

For example, “stress/strain charts” describe how the numerical value of s is related to the numerical value of e.  If a chart is to be quantitative, the dimension units that underlie s and e must be specified on the chart, or in an accompanying nomenclature.  Note that if the dimension units were not specified on Figures (1) and (2), the charts would be qualitatitive.

 

 

Conclusion

The new engineering science described herein should replace conventional engineering science because it is much easier to learn and apply, and because it greatly simplifies the solution of problems that concern nonlinear behavior.

 

References

Adiutori, E. F., 1974, The New Heat Transfer, pp. 1-14, 1-15, Ventuno Press

 

Adiutori, E. F., 1990, “Origins of the Heat Transfer Coefficient”, pp 46-50, Mechanical Engineering, August issue

 

Bejan, Adrian, 2013, Convection Heat Transfer, 4th edition, p. 32, John Wiley and Sons, Inc.

 

Fourier, J., 1822, The Analytical Theory of Heat, Article 160, 1955 Dover edition of the 1878 English translation, The University Press

 

Langhaar, H. L., 1951, Dimensional Analysis and Theory of Models, p. 13, John Wiley & Sons

 

Newton, I., 1726, The Principia,  3rd edition, translation by Cohen, I. B. and Whitman, A. M., 1999, p. 460, University of California Press

 

 

More about the new engineering.

The new engineering and its application are described in the following:

 

·   An 18 minute youtube video by Eugene F. Adiutori entitled “The New Engineering”.

 

·   The 2017 edition of The New Engineering by Eugene F. Adiutori.  Hardback copies

can be purchased at bookstores (ISBN 978-0-9626220-4-5) or Ventuno Press for $49.95.

 

        Ventuno Press, 1094 Sixth Lane N., Naples, FL  34102, USA

 

 

Eugene F. Adiutori

efadiutori@aol.com

 

 

Updated on November 4, 2018

 

 

Copyright ã 2017 by Eugene F. Adiutori

All material on this website may be downloaded and printed for personal use without charge, but may not be sold, reproduced by any means, or republished, without the written permission of the copyright owner.

 

Table of Contents

   

1.    Book entitled The New Heat Transfer.                 

 

a.     Narrative on writing and marketing The New Heat Transfer

 

b.     Downloadable copy of the first edition published in 1974.  

 

c.     Reviews.

 

d.       Reader comments

 

2.     The Russian edition of The New Heat Transfer (published by Mir, Moscow in 1977).

 

a.     Narrative on the Russian edition of The New Heat Transfer.

 

b.     Downloadable copy of the Russian edition.

 

3.    Modern engineering—the brainchild of Joseph Fourier (1822).

 

4.    Published papers

 

5.    Published letters and errata that concern the new engineering.

 

6.    Papers I presented at engineering conferences, none of which was deemed     good enough to warrant publication in an American Journal.

 

7.    Talks I was invited to give at AIChE and ASME dinner meetings.

 

8.    My patents.

 

9.     Narratives:

 

     a.  Debunking the myth that Newton conceived the heat transfer coefficient and the equation inappropriately referred to as “Newton’s law of cooling “ in most American heat transfer texts.

 

     b.  The storm of protest against “New Theory of Thermal Stability in Boiling Systems” published in Nucleonics in May of 1964, and my response.

 

c.      My 1964 paper that was accepted for publication in the AIChE Journal (but never published there), and the amazing view expressed by Professor Rohsenow (The paper was published in 1994 in the International Journal of the Japanese Society of Mechanical Engineering.  It was just as timely and important in 1994 as it had been in 1964.)

 

d.     The lecture Professor Graham B. Wallis invited me to give in 1965, and the errors and lack of attribution in his publications on thermal stability.

 

e.     My futile efforts to publish “A Transformed Moody Chart That Is Read Without Iterating”, including the mind-boggling rejection by the Editor of the ASME Journal of Fluids Engineering.