Journal “Thermal
Engineering” Volume 56, Number 6, June 2006
Currently, different handbooks used in science and technology are being
transferred from “paper” carriers to Internet sites. At present, if you need
the value of heat conductivity of brass at a certain temperature, it is easier
to type the key words “heat conductivity,” “brass,” and “temperature” into the
entry window of a search engine (www.yandex.ru,
www.google.ru, http://search.msn.com, etc) rather than
browse through a voluminous book. However, new problems (and solutions of
them!) of a special kind are emerging, and they are considered in this study.
The reliability of the information contained in
“paper” handbooks is to some extent ensured by the reputation of the
corresponding publishing houses and their staff of scientific consultants,
editors, and correctors. Internet sites are, as a rule, created by nonprofessional
developers and their content is not subject to strict editing and careful
proofreading procedures. Nevertheless, I have found a comparatively large
number of misprints in handbooks published by authoritative publishing houses.
For example, 0.02387 maybe printed instead of 0.02387 (i.e., the
digit 2 denoting the number of repeated zeros is misused), or 72.93 instead of
27.39 (in this case, the number was probably typed
The instrumental means considered below allow timely identification of
such typos in reference data or, at least, reduction of negative consequences
deriving from them.
Recently, tools for publishing documents on the
Web (on the Internet or corporative networks) created using applied
mathematical software have been multiplied greatly. In the case of Mathcad [1 –
4], the Mathcad Application Server [4 – 6] is the kit that is used for this
purpose. However, one can publish on the web, apart from pure calculation (examples
of such calculations for thermal power engineering are posted at www.vpu.ru/mas), hybrid forms consisting of
tables, plots, formulas (the dominant of “paper” reference information), and calculations.
The instruments built into these mathematical packets make it possible to carry
out statistical processing of tabular data and display the requested
information in an “intelligent” form. For example, having opened the page of a
“paper” handbook [7] containing information about the heat conductivity of
brass, one will see a table the side column of which contains a list of alloys,
including brasses of different composition, and a heading with the values o
temperature for which the values of heat conductivity are displayed in the
table. If one visits the Internet site located at http://twt.mpei.ac.ru/MAS/Worksheets/Therm/Heat_Cond_metal_e.mcd,
one will see the data shown in Fig. 1.
A visitor to this website may select the alloy
he is interested in the list, enter the value of temperature (in different
scales – Celsius, Kelvin, Fahrenheit, or Rankine), and obtain the required
value of heat conductivity (also in various units). The system also displays
plots showing dependence of heat conductivity on temperature, which makes it
possible to study the required quantity as a function of temperature and see
the current point on a curve. Moreover, a visitor to the website may set the
power n of the polynomial appro
Figure 1 displays
two plots: a spline interpolation (upper curve) and appro
Reference information also includes different
formulas needed for calculations. In this case, the Mathcad Application Server
may also prove to be very useful for publishing formulas on the Web.
Figure 3 shows as an example a web page
containing four formulas. These expressions describe a change in temperature in
a spherical wall under the conditions of steady heat transfer and with the heat
conductivity of the wall material not depending on temperature (a simplified
problem). The formulas are “animated”, i.e., the visitor can “play” with the
variables: change the initial data and see new values retrieved by the formulas
and the corresponding point on the plot, which also changes depending on the
initial data. “Animation of formulas serves two purposes. First, the visitor
can immediately obtain a result that follows from the formulas without entering
them into his computer or calculator. Second, this provides an extra option to
check whether the formula on the “paper” contained an error or the formula was
incorrectly typed into computer when creating respective Mathcad document
posted on the Web using the technology of the Mathcad Application Server. The
Mathcad package, which contains a mechanism for checking dimensions [8],
significantly reduces the probability of such errors. The Web page may contain
a hyperlink to a scanned “paper” page of the source, for example, a handbook or
even an experiment log (see the penultimate line in Fig.
3).
The formulas contained in the reference Web
pages may be transferred to other program environments either manually, in the
visual mode, or automatically. The most recent versions of the package, Mathcad
12 [4] and Mathcad 13, support recording of files used by this mathematical
package in HTML format (hyper text markup language). Therefore, it is now
possible to view and edit Mathcad files on a PC without using Mathcad itself.
Such a file posted on the Web for downloading (see the link in the lower part
of Fig. 3) may be opened by any word
processor. In this case, a reference formula presented in text format may be
copied to any program environment, for example, Maple (fig. 4), where the formula will be converted into a
graphical form more convenient for visual inspection.
The list of typos usually present in each handbook often contains as
well information about typos in formulas. This is a consequence of the formulas
being prepared for publication using equation editors, such as MS Equation,
rather than mathematical packages that allow testing of their “operability.”
Implementation of reference in the references
on the Web using instruments of mathematical packets and their tools for
graphic visualization makes it possible to represent information about the
functions of two or more arguments in an innovative form. The web page shown in
Fig. 5 displays not only values of entropy s, specific volume v, and enthalpy h of
water or steam in different units for the parameters specified by site the
visitor (steam pressure and temperature), but also the respective isotherm and
isobar on the respective thermodynamic surface with saturation lines for water
and steam (see also www.wsp.ru, the website of
the package WaterSteamPro [9], the functions of which were used for plotting
the thermodynamic surface shown in Fig. 5).
I have developed templates of Mathcad documents
for Web “animation” of various data: fully populated tables, scattered tables
with shifted arguments or diffused ranges, etc. [4]. The main amount of labor
is needed in this activity to digitize tables. I was assisted by the students
attending the course on information processing given at the
The calculations presented in Rotach’s textbook
are performed using the Mathcad environment. The reader can download the
calculation files from the site (see the third row in Fig. 6). Alternatively, he can handle them
interactively by changing the initial data and obtaining the result without
installing on his computer additional software, an operation that can be either
forbiddingly expensive or involve violation of license agreements.
The field of Internet handbooks based on
mathematical programs makes it possible to easily implement requests related
not only to separate points, i.e., fixed states of materials and coolants (see
Figs. 1 – 5), but to entire processes. For example, Fig.
7 shows the page of a Web-based reference (www.vpu.ru/mas)
displaying the process of isoentropic steam expansion, with the isotherm,
isobar, and other curves that characterize this process being displayed on the h,s chart as well. This website also
offers calculations and displays on the process charts of different expansion
processes specific to actual steam-turbine engines, gas-turbine engines,
combined cycle turbines, and “classical” cycles (Carno, Otto, Diesel, etc.).
Different sets of variables (h and s, t
and s, p and v, etc.) are
supported.
Currently, some books are in the process of
being digitized (see www.vpu.ru [12], www.thermal.ru [13], http://twt.mpei.ac.ru/GDHB [14], etc.).
The Moscow Power Institute publishing house is now preparing for publication
the fifth (additional) volume of handbook [7], containing a description of
methods that can be used for creation of Web-based interactive tabled, plots,
and formulas. Some chapters of this volume are already posted on the Internet
at http://twt.mpei.ac.ru/TTHB.
REFERENCES
1.
V.F.
Ochkov, V.F. Utenkov, and K.A. Orlov, “Thermal Engineering Calculations in the
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47 (2), 173-180 (2000)].
2.
V.F.
Ochkov, A.P. Pil’shchikov, et al., “Analysis of Ion-Exchange Isotherms Using
the Mathcad Software Package,” Teploenergetika, No. 7, 13-18 (2003) [Thermal
Engineering 50 (7), 537-543 (2003)].
3.
V.F.
Ochkov, A.P. Pil’shchikov, and Yu. V. Chudova, “Open Calculations in Thermal
Power Engineering,” Energosberezheniye I Vodopodgotovka, No. 1, 21-24 (2002).
4.
V.F.
Ochkov, Mathcad 12 for Students and Engineers
(BKhV,
5.
V.F.
Ochkov, “Mathcad: from Plot to Formula, from Computer Calculation to Internet
Calculation,” Exponenta Pro. Matematika v Prilozheniyakh, No.4, 84-85 (2003).
6.
V.F.
Ochkov, “Mathematical Packages: from Natural Economy to Production of Computer
Commodities via Internet,” ComputerPress, No. 5, 172-173 (2004).
7.
Theoretical Foundations of Thermal
Engineering. Thermal Engineering Experiment. Handbook, Ed. by A.V. Klimenko and V.M. Zorin
(Publishing House of the Moscow Power Institute,
8.
V.F.
Ochkov, Physical and Economic Quantities
in Mathcad and Maple (Finansy i Statistika,
9.
A.A.
Alexandrov, K.A. Orlov, and V.F. Ochkov, “Study of the Schemes for a
Combined-Cycle Plant with Steam Injection into the Gas Path on the Basis of
Development Applied Programs for the Properties of Working Fluids in
Combine-Cycle Plants,” Novoe v Rossiiskoi Elektroenergetike, No. 4, 27-31
(2004).
10.
V.F.
Ochkov, O.G. Osipov, and M.V. Volokitin, “New Approaches to Publication in
Industry Standards and Other Regulatory Documents Containing Calculations in a
Power Engineering Corporate Network,” Novoe v Rossiiskoi Elektroenergetike, No.
10, 21-25 (2005).
11.
V.F.
Ochkov, “Thermal
Engineering References in Internet,” Novoe v Rossiiskoi Elektroenergetike,
No. 4, 48-58 (2005).
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A.S.
Kopylov, V.M. Lavygin, and V.F. Ochkov, Water
Trearment in Power Engineering (Publishing House of the Moscow Power
Institute,
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14.
V.F.
Kasilov, Handbook on Gas Dynamics for
Specialists in Thermal Power Engineering (Publishing House of the Moscow
Power Institute,
