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CHAM, ie Concentration, Heat and Momentum Ltd


  1. The company and its early history
  2. The development of PHOENICS
  3. Limits and opportunities
  4. The Input-File Library as an example
  5. A lexicographical footnote

The company and its early history

CHAM was founded in 1974 by Professor Brian Spalding, who was then Professor of Heat Transfer at the Imperial College of Science and Technology in London, England. It moved to its present offices in Wimbledon in 1977.

Between 1974 and 1980, CHAM developed many computer codes for industrial clients in the aerospace, nuclear-power, fossil-fuelled power, chemical and automobile industries. Some of these found their way into the public domain.

Computers then had small memory and slow execution; so ingenious programming was needed to enable industrial problems to be solved. Moreover, there was much scepticism among experienced engineers as to whether computer simulation of complex turbulent and multi-phase flows could ever be of practical use.

Gradually the doubters were won over; but they had not been wholly wrong: making realistic flow simulations economically WAS difficult.

2. The development of PHOENICS

By 1980, the difficulties of maintaining high quality for a large number of codes were mounting; so CHAM decided to create a single package, capable of handling all the equation types and physical phenomena which were treated by any of the individual ones. The result was PHOENICS, an acronym for:

Parabolic Hyperbolic Or Elliptic Numerical Integration Code Series

"Parabolic", "hyperbolic" and "elliptic" were the terms for the relevant equation types. Interestingly, PHOENICS is still the only general-purpose code for which the P and the H are appropriate.

This was the world's first general-purpose CFD code. It was launched commercially in 1981 as a Fortran-input code, was updated in 1984 as an interactive-input one, then reached a plateau of stability in 1987 with PHOENICS-1.4, and has since continued to grow in strength and capability, culminating (for the moment) in PHOENICS.

As a consequence of its early start, and of the wide spread of its shareware version, PHOENICS is today the most widely-used CFD code in the world; and its users are still growing in number.

These users commmunicate with each other by means of the PHOENICS Journal, and by participation in national and international PHOENICS User Conferences.

However PHOENICS itself can be the most effective communication means facilitating serious contributions to the CFD world; for its structure allows users to supply entries in the Input-File Library (LibrarieS for version 2 and above), to attach and circulate Fortran -coding modules with new physical or numerical content.

Needless to say, the users of PHOENICS also help CHAM greatly by finding bugs and blemishes which CHAM has not itself discovered but is glad to put right.

PHOENICS carries, in POLIS, its on-line information system, an Applications Album. Users are encouraged to supply text-and-picture entries for this, thereby publicising their PHOENICS-based works, to everybody's advantage.

3. Limits and opportunities

[ The following section was written several years ago; but it has been allowed to remain because of its significance as a prophecy, namely as one which has turned out, as do even the best, to be partly wrong as well as partly right. Perhaps PHOENICS does not occupy so central a role on the CFD scene as its writer expected; but that the PHOENICS example has been followed is certainly true.]

There exist products which, once released into the world, become in some sense common property. MS-DOS, and the WINDOWS, are of course uniquely associated with the Microsoft Corporation; but independent authors write books about it. Model-T fan clubs exist which are in no way creatures of the Ford Corporation; and writers on the works of William Shakeseare require neither permission nor funding from Stratford-on-Avon.

The originators of such products, if they are still in a position to reflect on these developments, should welcome them; for to organize them themselves would be at best a distraction from their prime tasks, and would soon in any case exceed their strengths.

So it is now with PHOENICS. CHAM has invented a language, of which PHOENICS is the embodiment, and launched it into the world. What the world does with it is beyond CHAM's control. It is for the PHOENICS users now, if they wish, so to act collectively as they think fit. CHAM will of course assist, when asked ; but it cannot hope and should not strive to take all the initiatives itself.

4. The Input-file Library as an example

The PHOENICS Input-File Library exemplifies the opportunities which exist. Even the library of the lowest Shareware version PHOENICS- 1.4-EO contains several hundred examples. They are valuable; yet, in comparison with what the code is capable of on the one hand, and with the needs of its users on the other, these examples are pitifully inadequate.

A comprehensive library for students of engineering, say, would include sections on:

PHOENICS is capable of providing instructive simulations of all the above phenomena and processes, and indeed of exemplifying the numerous alternative numerical techniques of representing them.

Yet CHAM itself is unlikely ever to have the resources, or the appropriately-trained and -motivated staff, to make a reality of the idea outlined.

Who will? Surely there must be somewhere in the world persons, or groups, with the energy, vision and ability to command resources, which the task requires.

With persons who desire to avail themselves of the opportunity, CHAM will gladly cooperate; for, having been nurtured in an academic environment, and having perforce to rely heavily on the findings of the world's scientific community, CHAM will do all in its power to foster continuing education and research.

It is for this reason that, since the November 1994 issue of PHOENICS Shareware, CHAM has "unlocked the library door", so as to make it easy for all users to supply new examples, to augment and improve existing ones, to supply appropriate PHOTON command sequences and to translate the text into other languages than English.

The SATELLITE HELP file has been similarly opened up.

CHAM now stands ready to receive contributions from PHOENICS users in all parts of the world, to assemble them into orderly packages, and to distribute them as Shareware in the speediest and most economical way possible.

5. A lexicographical footnote

The CH in CHAM is pronounced as in CHurCHill, CHimpanzee and CHatanooga CHoo-CHoo, not as in Champagne and Chicago.

Shakespeare used the word as a name for the Khan of the Tartar hordes ("Pluck me a hair from the Great Cham's beard").

Samuel Johnson, the eighteenth-century English lexicographer, was referred to with reverence as the "Grand Cham of Literature".

In some Slavic languages, unfortunately, "cham" signifies a "low fellow" or "lout". Possibly those peoples had good reason to dislike anything associated with Tartars!

CHAM's staff have always been multi-cultural; so Christian (or Confucian), Hindu And Muslim has sometimes seemed to be an appropriate expansion of the acronym.

CHAM in the present context is simply an acronym, derived from the full name of the company:

Concentration, Heat And Momentum Ltd

which was chosen by its founder partly because the company's computer programs calculate the CONCENTRATIONs of chemical species, the rates of HEAT transfer AND the distributions of the components of MOMENTUM, in fluids and solids of all kinds.

It was also chosen to convey the idea that work of its kind requires CONCENTRATED attention,

proceeds at a HOT pace,

and must maintain its MOMENTUM, if it is to continue to be successful.