modelTurbine
Extends from BaseClasses.TurbineBase (Gas Turbine).
Information
This model adds the performance characteristics to the Turbine_Base model, by means of 2D interpolation tables.The performance characteristics are described by two characteristic equations: the first relates the flow number phic, the pressure ratio PR and the referred speed N_T; the second relates the efficiency eta, the flow number phic, and the referred speed N_T [1].
The performance maps are tabulated into two differents tables, tablePhic and tableEta which express phic and eta as a function of N_T and PR respectively, where N_T represents the first row and PR the first column [2]. The referred speed N_T is defined as a percentage of the design referred speed.
The Modelica.Blocks.Tables.CombiTable2D interpolates the tables to obtain values of referred flow and efficiency at given levels of referred speed.
Modelling options
The following options are available to determine how the table is defined:
- Table = 0: the table is explicitly supplied as matrix parameter.
- Table = 1: the table is read from a file; the string fileName contains the path to the files where tables are stored, either in ASCII or Matlab binary format.
References:
- S. L. Dixon: Fluid mechanics, thermodynamics of turbomachinery, Oxford, Pergamon press, 1966, pp. 213.
- P. P. Walsh, P. Fletcher: Gas Turbine Performance, 2nd ed., Oxford, Blackwell, 2004, pp. 646.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | explicitIsentropicEnthalpy (from TurbineBase) | true | isentropicEnthalpy function used |
| SI.PerUnit | eta_mech (from TurbineBase) | 0.98 | mechanical efficiency |
| Medium.Temperature | Tdes_in (from TurbineBase) | inlet design temperature | |
| Boolean | allowFlowReversal (from TurbineBase) | system.allowFlowReversal | = true to allow flow reversal, false restricts to design direction |
| SI.AngularVelocity | Ndesign | Design speed | |
| Real[:,:] | tablePhic | fill(0, 0, 2) | Table for phic(N_T,PR) |
| Real[:,:] | tableEta | fill(0, 0, 2) | Table for eta(N_T,PR) |
| String | fileName | "NoName" | File where matrix is stored |
| TableTypes | Table | TableTypes.matrix | Selection of the way of definition of table matrix |
| Initialisation | |||
| Medium.AbsolutePressure | pstart_in (from TurbineBase) | inlet start pressure | |
| Medium.AbsolutePressure | pstart_out (from TurbineBase) | outlet start pressure | |
| Medium.Temperature | Tstart_in (from TurbineBase) | Tdes_in | inlet start temperature |
| Medium.Temperature | Tstart_out (from TurbineBase) | outlet start temperature | |
| Medium.MassFraction[Medium.nX] | Xstart (from TurbineBase) | Medium.reference_X | start gas composition |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Mechanics.Rotational.Interfaces.Flange_a | shaft_a (from TurbineBase) | ||
| Modelica.Mechanics.Rotational.Interfaces.Flange_b | shaft_b (from TurbineBase) | ||
| FlangeA | inlet (from TurbineBase) | ||
| FlangeB | outlet (from TurbineBase) |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| ThermoPower.System | system (from TurbineBase) | System wide properties | |
| Medium.BaseProperties | gas_in (from TurbineBase) | ||
| Medium.BaseProperties | gas_iso (from TurbineBase) | ||
| SI.Angle | phi (from TurbineBase) | shaft rotation angle | |
| SI.Torque | tau (from TurbineBase) | net torque acting on the turbine | |
| SI.AngularVelocity | omega (from TurbineBase) | shaft angular velocity | |
| Medium.MassFlowRate | w (from TurbineBase) | Gas flow rate | |
| Medium.SpecificEntropy | s_in (from TurbineBase) | Inlet specific entropy | |
| Medium.SpecificEnthalpy | hout_iso (from TurbineBase) | Outlet isentropic enthalpy | |
| Medium.SpecificEnthalpy | hout (from TurbineBase) | Outlet enthalpy | |
| Medium.AbsolutePressure | pout (from TurbineBase) | Outlet pressure | |
| SI.PerUnit | PR (from TurbineBase) | pressure ratio | |
| SI.PerUnit | eta (from TurbineBase) | isoentropic efficiency | |
| Real | N_T | Referred speed | |
| Real | N_T_design | Referred design speed | |
| Real | phic | Flow number | |
| Modelica.Blocks.Tables.CombiTable2D | Phic | ||
| Modelica.Blocks.Tables.CombiTable2D | Eta |
Revisions
- 13 Apr 2005
by Francesco Casella:
New method for calculating performance parameters using tables. - 14 Jan 2005
by Francesco Casella:
Adapted to Modelica.Media. - 5 Mar 2004
by Francesco Casella:
First release.
Turbine model restructured using inheritance.