Forbes Brown

FORBES T. BROWN

Professor of Mechanical Engineering, emeritus
Lehigh University
Bethlehem, PA 18015
email: ftbmhb@aol.com
phone: 610-865-4137

Degrees and Positions

S.B. and S.M. in Mechanical Engineering, M.I.T., 1958
Mech.E., M.I.T., 1959
ScD in Mechanical Engineering, M.I.T., 1962

M.I.T. positions:
Research and Teaching Assistant, 1956-1958
Instructor, 1958-1962
Assistant Professor, 1962-1966
Associate Professor, 1966-1970

Lehigh position:
Professor , 1970-2004

Fields of professional interest: Dynamic systems and control (chaired Mechanical Systems Division at Lehigh U.), fluidics (chaired ASME committee with that name), fluids engineering (chaired ASME division with that name), fluid power (was member of board, NCFP), graphics, dynamics, thermodynamics, design and especially the modeling of dynamic systems (see textbook). Was active in curricular matters for the department, college and university.

This website is under construction. For the present, it is focused on the immediate need for information regarding the new THERMOSIM software. [Posted October, 2014]

ANNOUNCEMENT

Release 2.0 of THERMOSIM® is available for the dynamic simulation of a wide variety of thermodynamic and many other engineering systems represented by bond graphs, including a powerful graphical interface. Details below.


THERMOSIM® is a user-friendly package for the dynamic simulation of engineering systems that can be modeled with a modest number (usually less than 100) lumped elements. It has unique capabilities whenever flowing fluids or chambers with compressible fluids are present. It employs convection bond graphs, a creation of F. Brown. Otherwise it employs fully compatible conventional bond graphs. The thermodynamic properties of thirty-five generally two-phase substances and four liquids are efficiently computed with the help of a large number of empirical models including derivatives that speed up the convergence of iterations. Boiling and condensing flows in channels are treated automatically. Hydraulic systems are treated with the same thermodynamic rigor as systems with two-phase fluids, including application of the second law of thermodynamics as well as the first law. Systems or parts of systems not requiring convection bonds are integrated seamlessly, including compliances defined only by analytic expression for stored energy, such as for electromechanical components . It can also handle systems for which you have differential equations but no bond graph. Since linearity is rarely assumed, the package does not include the linear analysis which is a feature of other bond-graph based simulation packages. The simulations are carried out using MATLAB®, the basic parts of which you must have available on your computer.

The package is built upon the older Thermodynamic Package, which had no graphical interface, could not compute heat transfer in channels or treat hydraulic systems. Beta Release 1.0 was issued in July, 2014, and the present Beta Release 2.0 in October, 2014. Make sure you have the latest version of the files that you choose to use, since many changes including some corrections have been made.

There are various sets of files associated with THERMOSIM. To download, click on the name in red. Items 1, 2, 4 and 5 have been upgraded over Release 1.0.

1.  The Users’manual, The THERMOSIM Package for Simulating Thermodynamic, Hydraulic and Other Engineering Systems, Release 2.0 (UPDATED), 88 pages, is a Microsoft Word or pdf document that will help you decide whether to download the software as well as how to use it.  New features and several new examples have been added to the previous release.  It is intended for those with little knowledge of bond graphs as well as those who are simply unfamiliar with the special convection bonds and elements.  It employs a case-study approach with numerous examples, and includes detailed information on creating system models and displaying results.  Selected references are included.

2. To acquire the BondGrapher software itself (BondGrapher.exe and a couple ancillary files) you should contact F.Brown directly, using the email address above, at least until further notice.  There is a simple freeware agreement, and we want to know who you are in order to provide updates and get feedback.  The Help files need repair, unfortunately.  This software was written by Scott A. Brown, a software engineer, who happens to be F. Brown’s son.  All other relevant  software is by F. Brown and may be downloaded below.

3. MATLAB data files for 39 individual substances, comprising extensive sets of constants used to develop analytic expressions for thermodynamic and other properties.  You will likely not need many of these.  At this writing, viscosity and thermal conductivity data needed for the IRS element is present only for the four liquids plus the refrigerant R12.  More should be added shortly.

To download these files in a zipped (compressed) folder, right-click here: datfiles.zip

 

Date entered

File name

Function

1

June 2014

datMILH5606

Data file for hydraulic fluid MIL-H-5606

2

June 2014

datMILPRF27601.m

Data file for the hydraulic fluid MIL-PRF-27601

3

June 2014

datMILPRF823282

Data file for the hydraulic fluid MIL-PRF-823282

4.

Feb. 2010

datammonia.m

Data file for ammonia

5.

Feb. 2010

datargon.m

Data file for argon

6.

Feb. 2007

datbutane.m

Data file for butane

7.

Feb. 2010

datcarbondioxide.m

Data file for carbon dioxide

8.

Feb. 2007

datcesium.m

Data file for cesium

9.

Feb. 2007

datethane.m

Data file for ethane

10.

Feb. 2007

datethylene.m

Data file for ethylene

11.

Feb. 2007

dathelium.m

Data file for helium-4

12.

Feb. 2007

dathelium2.m

Automatically called when needed

13.

Feb. 2007

dathelium3.m

Automatically called when needed

14.

Feb. 2007

datheptane.m

Data file for heptane

15.

Feb. 2007

dathexane.m

Data file for hexane

16.

Feb. 2007

dathydrogen.m

Data file for hydrogen (para)

17.

Feb. 2007

datisobutane.m

Data file for isobutene

18.

Feb. 2007

datisopentane.m

Data file for isopentane

19.

Feb. 2007

datlithium.m

Data file for lithium

20.

Feb. 2007

datmercury.m

Data file for mercury

21.

Feb. 2007

datmethane.m

Data file for methane

22.

Feb. 2007

datneon.m

Data file for neon

23.

Feb. 2010

datnitrogen.m

Data file for nitrogen

24.

Feb. 2007

datoctane.m

Data file for octane

25.

Feb. 2007

datoxygen.m

Data file for oxygen

26

Feb. 2007

datpentane.m

Data file for pentane

27.

Feb. 2007

datpotassium.m

Data file for potassium

28.

Feb. 2007

datpropane.m`

Data file for propane

29.

Feb. 2010

datpropylalcohol.m

Data file for propyl alcohol

30.

Feb. 2007

datpropylene.m

Data file for propylene

31.

June 2014

datR12.m

Data file for refrigerant R12

32.

Feb. 2010

datR13.m

Data file for refrigerant R13

33.

Feb. 2010

datR22.m

Data file for refrigerant R22

34.

Feb. 2010

datR23.m

Data file for refrigerant R23

35.

Feb. 2010

datR134a.m

Data file for refrigerant R134a

36.

Feb. 2010

datR502.m

Data file for refrigerant R502

37.

Feb. 2007

dat503.m

Date file for refrigerant R503

38.

Feb. 2007

datrubidium.m

Data file for rubidium

39.

Feb. 2007

datsodium.m

Data file for sodium

40.

Feb. 2010

datwater.m

Data file for water

41

Feb. 2010

datliqwater.m

Data file for liquid water


4. MATLAB files that run a simulation or use the data above to develop analytic expressions for thermodynamic and other properties (usually 18 different properties or derivatives of properties used to expedite iterations).  You will likely need most of these.  To download them in a zipped (compressed) folder, click here: simulationfiles2.zip

 

Date entered

File name

Function

1.

Oct. 2014

THERMOSIM2.m

Program called by your system file to control the simulation

2.

Oct. 2014

convec2.m

Primary simulation file when using a general substance

3.

Oct. 2014

IRS2.m

Script file to accompany convec2.m for IRS elements

4.

July 2013

boiling.m

Function file called by IRS2.m

5.

Oct. 2014

convRS2.m

Function file for RS (fluid restriction) elements

6.

Oct. 2014

therprop2.m

Called automatically or by user for properties of 2-phase fluids

7.

July 2013

vapor1.m

Called automatically by therprop.m

8.

July 2014

vapor2.m

Called automatically by therprop.m

9.

July 2014

vapor3.m

Called automatically by therprop.m

10.

June 2014

vapor4.m

Called automatically by therprop.m

11

June 2014

vapor5.m

Called automatically by therprop.m

12.

June 2014

vapor6.m

Called automatically by therprop.m

13.

May 2010

vapor7.m

Called automatically by therprop.m

14.

June 2014

vapor8.m

Called automatically by therprop.m

15.

June 2014

airmix.m

Called automatically for wet air as a mixture of substances

16.

Oct. 2014

convecliq2.m

Primary simulation file when using a liquid

17.

July 2014

IRSliq2.m

Script file to accompany convecliq2.m for IRS elements

18.

July 2014

liqprop2.m

Called automatically or by user for properties of liquids

19.

Sept. 2014

DISPLAY2.m

Script file for displaying running time and results


5. MATLAB “system files” generated by BondGrapher for the 19 examples in the Manual that go that far. To download these files in a zipped (compressed) folder, click here: systemfiles2.zip

File Name

Description

Date

catapult2.m

System file for the steam catapult, pp 4-8, p. 60

Oct. 2014

compbasic.m System file for predecessor for compfin.m , p.  51 Oct. 2014
compfin.m Finned compressor of Heidari and Rufer, pp. 51-53 Oct. 2014
compressorloop.m Compressor (R12 fluid) with 100% efficiency, simple load, pp. 57-5 Oct. 2014

tankchgwetair2.m

System file for charging a tank with wet air, pp 15-18

Oct. 2014

pumpaccum2.m

System file for hydraulic pump charging an accumulator, pp. 17-21

Oct. 2014

comptank2.m

System file for a steady-state compressor charging a tank, pp. 22-23

Oct. 2014

aircompsys2.m System file for piston-cyl. comp., tank and actuator, pp. 23-26, 42-45 Oct. 2014

hydpipe2.m

System file for hydraulic tube flow with inertia, pp. 28-29

Oct. 2014

hydsys2.m

System file for hydraulic system with load, pp. 46-50

Oct. 2014

hydsysmod.m Above system but with 100% efficient pump, pp.  57-58 Oct. 2014

heatpump2.m

System file for heat pump, pp. 29-32, 53-57, 81-83

Oct. 2014

GEMwetair2.m

Ground-effect machine with nonlinearities, pp. 38-42

Oct. 2014

DCmotor2.m

Simple DC motor and load, pp. 63-64

Oct. 2014

Embalance2.m

Electromechanical balance using Cf fields, pp. 67-70

Oct. 2014

gyroscope2.m

Dynamics of a gyroscope, pp. 75-80

Oct. 2014

rockdrill2.m

Rockdrill powered by compressed wet air;p. 57

Oct. 2014

solenoid2.m

Energy-defined solenoid with stiction, load; pp. 65-66

Oct. 2014

rootsblower.m Approximate dynamic model of Roots blower in the textbook; p. 59 Oct. 2014

6.  The file 2014 paper is the 2014 ICBGM paper in which THERMOSIM is being introduced in a presentation on July 9, 2014.  It is essentially a synopsis of the Users’ Manual, so you probably will have no use for it.

7.  The file 2012 paper gives one of the references in its entirety.  It includes information about energy-based modeling.  It is pre-BondGrapher, but describes the example of the solenoid system (solenoids1.m), which is not in the Users’ Manual, and gives more information about the electromechanical balance (EMbalance1.m), which is.

8.  The file 2010 paper gives the first of two parts of a paper that includes contains information about the rock drill (rockdrill1.m), which also is not in the Users’ Manual.

9.  The file Plenary 2007 ICBGM.ppt is a slide show that presents pre-THERMOSIM convection bond graphs.  It was much more complicated, but may be of interest to a few who would appreciate the background.