### Thank you very much for your kind interest in Organism®.

A word about Organism; it will be an Engineering focused web service principally focused as a browser based UI served by a back end that provides dimensional analysis. It will fundamentally be free of charge and mostly but not completely open source.

A simple example of ‘dimensional analysis’ would be as follows;

If I have a glass of water in front of me, and I desire to know the mass of water in the glass, I can measure with a ruler the Inner Diameter (I.D.) of the glass. From this I.D. the cross sectional area may be calculated and the depth of water in the glass measured. With these values and some knowledge of the physical nature of the fluid in the glass (the water) we may determine the mass of water in the glass.

1.) I.D. of Glass (ID) = 2.00 in;

2.) Cross Sectional Area of Glass (XA) = ¼π ID² = 3.14 in²;

3.) Depth of water in glass (h) = 3.00 in;

4.) Volume of water in glass (V) = h * XA = 3.00 in * 3.14 in² = 9.42 in³;

5.) Density of water (D) = 0.036 lbm/in³

6.) Mass of water in glass = V * D = 9.42 in³ * 0.036 lbm/in³ = 0.339 lbm

** NOTE: this is understood to be a trivial example, deliberately so.

Step 4 illustrates the ‘multiplication of units’ by addition of the exponents in * in² = in³ (no exponent implies the value of ‘1’)

Step 6 shows ‘cancellation units’ ~~in³~~ * lbm/~~in³~~ = lbm

It is appropriate now to note that Organism® is “unit agnostic”, meaning it ignores the unit and ‘sees’ the underlying dimension behind the unit, (see Physical Quantities for discussion what is meant by dimensions). I prefer to use the term dimensionality over dimension to emphasize the broader usage intended, beyond simply…

a measurement of the size of something in a particular direction, such as the length, width, height, or diameter

### Reynolds Number in Organism^{®}

*'The Cheese becomes more binding'*when we consider a non-trivial example to diplay the capabilities of Organism®.

The above example displays the utility of dimensional analysis (a checker can see that the inputs to the calculation are length and knows that the function applied to convert diameter to area squares the diameter both the numeric value and unit (in), further knows that density is in units of mass per volume, and I know that the desired result should be in pound mass (lbm). As a checking engineer I can follow the numeric AND unit arithmetic and observe that the result is correct. This is, as noted, a trivial example; it becomes a bit more interesting if considering a Reynolds Number calculation, specifically for flow in a pipe or tube, the Reynolds number may be defined as:

(A) (B) (C)

where:

· *D** _{H}* is the hydraulic diameter of the pipe; its characteristic traveled length,

*L*, (m).

· **Q** is the volumetric flow rate (m^{3}/s) **{length : 3, time : -1}

· *A* is the pipe's *cross-sectional* area (m^{2}) **{length : 2}

· **v** is the mean velocity of the fluid (m/s) **{length : 1, time : -1}

· *μ* is the dynamic viscosity of the fluid (Pa·s = N·s/m^{2} = kg/(m·s)) **{length : -1, mass : 1, time : -1}

· *ν* (nu) is the kinematic viscosity (*ν* = *μ/**ρ)* (m^{2}/s) **{length : 2, time : -1}

· *ρ* is the density of the fluid (kg/m^{3}) **{length : -3, mass : 1}

**SI Base units give additional insight into what is meant by dimensionality

**Data Set**

{scalar : 1.2, length : 3, time : -1}

{scalar : 0.67, length : 1}

{ scalar : 0.89, length : 2, time : -1}

{ scalar : 0.35, length : 2}

ANSWER = “C” is the equation to use the above data.

Imagine for a moment we don’t know we need a Reynolds Number but we have the above Data Set… and are not sure what to do with it. As will be covered in a moment solving this problem is worth thinking about. In this case we can add to our data set that the desired result is a dimensionless number (without knowing it to be the Reynolds Number), there are ONLY two ways to combine the above data to yield a dimensionless value, the first being a Reynolds Number, and the second being the ‘Inverse of a Reynolds Number’ (which is nonsensical and may be dismissed). In the above case no “Function call” (function = “Reynolds_Number”) is required; it is only required that the Data Set be defined. Given the required data set, Organism^{®} can provide the Reynolds Number, no function call is required; it may be said to be an eager service.

Pull out a “hydraulic book”, pull out a “Perry’s Handbook of Chemical Engineering” or a “Mark’s Standard Handbook of Mechanical Engineering”, I believe you will be astonished at how frequently the “Function call” is fully defined by the Data Set. Where this condition is not met, we can add that calculations live in a context that includes (per engineering best practice) a narrative description of what is calculated, maybe a sketch and a symbolic and verbose description of the data set. Words and Phrases like “Hydraulic Diameter, Volumetric Flow Rate, Pipe, and viscosity all point to a Fluid Flow problem domain, and these are also fed into Organism^{®} to aid in resolving ambiguous conditions.

So Organism is an “Eager Service”, so what? Imagine for a moment, something like an Excel Spreadsheet, living on the “Cloud” and exposed to every engineer on the planet. Further imagine that this spreadsheet has a function call for every calculation you and every other engineer has ever used. Regrettably this would be totally useless because you would have no way to know what cell a desired calculation was in (you would not know the “Function Call”). This is where the eagerness offered by Organism® becomes essential, because it is the job of Organism® to fetch the function with the information available to it. The result of this architecture is a browser based program that provided a web connection will make every effort to anticipate what a user needs to do, even if the user is not totally sure about it.

Organism is already equipped with an EoS for Water (International Steam Tables), Black Oil models, Tables for NPS Pipe a number of hydraulic flow calculations, a means of calculating molecular weights based on chemical formula. The structure and architecture of Organism® facilitate the expansion of the platform to include new functions and domains.

When I talk about an Engineering Ecosystem, I am envisioning a platform where Calculations, Heat and Mass Balances, PFDs, P&IDs, Equipment Data Sheets all reside in a single cloud repository and accessible by teams as required. This then supports online project execution, scheduling, purchasing and logistics.

Many thanks and best regards,

Steve Bolman P.E .*Organism is a registered trademark of Equalation, LLC*