EBSILON®Professional Online Documentation
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Line connections |
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1 |
Inlet |
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2 |
Outlet |
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General User Input Values Displays
In logical constructions, this component serves to map physical quantities that are only available as result values or as derived quantities onto the three basic quantities mass flow, pressure, and enthalpy, which are used as variables in Ebsilon.
This allows to access all these values during the calculation, e.g. for closed-loop controls or arithmetic operations.
The flags FMAPM, FMAPP, and FMAPH serve to set which input variable is to be mapped onto the mass flow / the pressure / the enthalpy of the outlet line. This mapping is always carried out in the Ebsilon default units: if e.g. a temperature is mapped onto a mass flow, 20°C is mapped onto 20 kg/s. In the result values RM, RP, and RH, however, the original dimensions are retained. There it would be possible to have 68°F displayed instead of 20°C.
The available input variables are described below.
FMAPx between 1 and 31
As long as flow velocities are very small compared to sonic velocity, it is not necessary to differentiate between total and static quantities. For higher velocities, however, kinetic fractions are no longer negligible. Here it has to be noted that the quantities shown on the lines in Ebsilon are always total quantities, i.e. the kinetic fraction is always included. This allows to allocate constant values to a line in Ebsilon, e.g. for the enthalpy, as the total enthalpy remains constant even if the pipe cross section and thus the flow velocity changes.
The breakdown into static enthalpy and kinetic energy, by contrast, depends on the flow velocity at the respective location of the line. Determining the static quantities therefore requires to know the flow velocity at the respective location of the line.
Therefore it can be specified by means of Component 1 or 33 (General input value / start value) in Ebsilon; here it is possible to use several Components 33 with different velocities. The static quantities are then obtained as result values of the respective start value.
As the result values can only be further processed in EbsScripts, Component 168 now allows to transfer these quantities onto lines. FMAPx = 1 to 23 are available for this purpose.
In component 168, you may specify either the velocity directly (VEL_SET), or the diameter (D_SET) or the cross area (A_SET) to determine the velocity. By using Z_SET the potential energy can be considered as well. See component 1 for more details.
You may use different components 168 with different velocities at the same pipe.
To facilitate the modeling of flight propulsion systems (which was the request that motivated the development of this component), FMAPx=31 also allows to directly transfer the thrust (= mass flow * velocity).
With FMAPx between 100 and 200, mass flows (absolute and molar) as well as energy flows (sensible, latent, total) can be displayed, and also the NCV, entropy, exergy, and geodetic height (the air pressure converted into height above sea level).
With FMAPx between 200 and 300, material fractions can be displayed. Here the substance whose fraction is to be displayed has to be selected in the respective FSUBSTx:
For this purpose, an individual element has to be selected at FSUBSTx, i.e. not a compound. In doing so, both conventional elements and NASA elements can be used. It is also possible to select “ash“, which then contains the fraction that does not consist of the conventional Ebsilon elements.
For instance: a binary fluid line with a water/LiBr mixture cannot be conventionally broken down into H, O, and ash. LiBr is treated as “ash“ because it does not consist of conventional Ebsilon elements. If, by contrast, NASA: Li and NASA: Br are used, the LiBr is broken down too.
301, 302, and 303 yield the fraction of the fluid that is in the gaseous, liquid, and solid phase respectively.
311 to 317 treat humid air:
321 to 349 refer to a certain phase transition in each case:
namely
351 and 352 yield the pressure and temperature of the triple point.
361 and 362 yield the pressure and temperature of the critical point.
Calls With FMAPx between 400 and 500, various physical properties functions can be displayed (specific heat, speed of sound, gas constants...).
FMAPx between 500 and 600 allow to access values of shafts and electric lines.
501 and 511 are only available on shafts and electric lines, 512 only on shafts, and all others only on electric lines.
501 to 507 yield powers (active/reactive/apparent power) and quantities related to power like the power factor (cos(phi)), phase shift between current and voltage, and the number of phases.
511 to 512 yield rotational speed and frequency repectively and torque.
521 to 545 enable access to values regarding
This information is partly determined by means of internal additional information that is not part of the equation system. Only 521 and 531 indicate the line value of the current and voltage respectively.
FMAPx with the final digit 2 yields the real part and with the final number 3 the imaginary part of the respective quantity. With the final digit 4 you obtain the phase (related to the zero point “mass“) and with the final digit 5 the amount. Normally, it should correspond to the line value. However, this additional information is not available for each electric line.
You have access to the specification and result values of component 117 (sun).
By connecting the logic output of the sun (2) to the input of component 168, the specification and result values can be read and transmitted to the output line as mass flow, pressure or enthalpy. For this, FMAPx must be set to
By connecting the output of device 168 to the logic input (1) of the sun, the specification values of the sun can also be overwritten with the values that device 168 has converted from mass flow, pressure or enthalpy to the appropriate specification value. Flags and integer values (like the sun index) are excluded. However, it is possible to convert the time into the number of days since 12/30/1899. The time is viewed as a fraction of the day, e.g. 6 a.m. = 0.25. To ensure that the current result values are available during the iteration, the setting “Calculate result values in each iteration step” must be activated for the sun component.
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FMAPM |
Quantity mapped to the massflow at outlet - see values described above in chapter General 0: unused |
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FSUBSTM |
Substance to be used by FMAPM, valid only for FMAPM between 201 and 205 |
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FMAPP |
Quantity mapped to the pressure at outlet - see values described above in chapter General 0: unused |
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FSUBSTP |
Substance to be used by FMAPP, valid only for FMAPP between 201 and 205 |
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FMAPH |
Quantity mapped to the enthalpy at outlet - see values described above in chapter General 0: unused |
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FSUBSTH |
Substance to be used by FMAPH, valid only for FMAPH between 201 and 205 |
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VEL_SET |
Flow Velocity inside the pipe, valid only for FMAPx < 32 |
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A_SET |
Cross section area of the pipe, valid only for FMAPx < 32 |
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D_SET |
Inner diameter of the pipe, valid only for FMAPx < 32 |
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Z_SET |
Altitude above sea level of the center of the pipe cross section - to consider the potential energy too, valid only for FMAPx < 32 |
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Display Option 1 |
Click here >> Bauteil 168 Demo << to load an example.