Turbomachine
Components
Cycle-level
analysis of jet and rocket engines, power generation
cycles, heat pumps and refrigeration cycles, etc.
can be performed using performance map-based descriptions
of single- or multi-stage pumps, fans, turbines,
and compressors. These elements predict flows and
pressure drops, using either directly input maps
(single curves or multiple curves per shaft speed)
of flow versus pressure drop, or maps specified using
equivalent states, reference states, head and flow
coefficients, etc. Isentropic efficiencies may be
specified, enabling the code to predict shaft power
and hydraulic torque. Tables of flow and efficiency
relationships are normally input, but options exist
for functional (algorithmic) descriptions as well
as links to turbomachine design software.
Pumps: Reference speeds or flow/head coefficients (to exploit
pump similarity laws), cavitation detection and modeling
(based on either NPSH or Nss) , viscosity corrections,
and two-phase flow degradations. Nonmonotonic curves
(with positively sloped regions) are permitted.
Turbines: Equivalent conditions, including equivalent speed
options available. Handling of choking and truncated
tables, and two-phase outlet states. Total-total,
total-static, and other inlet/outlet state options.
Efficiency may optionally be a function of U/C: the
blade tip velocity to isentropic spouting velocity
(or fluid jet velocity) ratio. Power (or equivalent
power) may be specified instead of efficiency.
Compressors
(Variable displacement): Equivalent conditions, including
equivalent speed options available. Handling of choking
and surge regimes. Total-total, total-static, and
other inlet/outlet state options. Power (or equivalent
power) may be specified instead of efficiency. Nonmonotonic
curves (with positively sloped regions) are permitted.
Compressors
(Positive displacement): Flow specified via volumetric
efficiency (versus speed and/or pressure ratio) and
displacement volume. Power may be specified instead
of isentropic efficiency.
Engines
and Cycles
Design
and analysis of engine or power cycles can include
single- or two-phase flow components such as boilers,
condensers, regenerative heat exchangers, control
valves, etc. in either steady or unsteady analyses.
For systems with interconnected turbomachines (e.g.,
turbochargers, turbopumps, turbojets, etc.), shaft
speeds can be predicted to balance torques in steady-states,
or shaft/gear mechanical speeds can be solved in
transients concurrent with the cycle thermohydraulics.
Secondary
Flows
Extensive
options exist for modeling passages within rotating
machinery, including between rotating and stationary
parts. Analysis of secondary coolant, leakage, or
lubricating flows can exploit built-in correlations
or user-supplied correlations for friction, heat
transfer, and torque.
Turbocharger
Sample Model
A
sample model of a turbocharger
system is available
for demonstration purposes.
Validation
Case
Advanced
Liquid Oxygen Turbopump
For
More Information
Customization
and Consulting
CRTech
also provides consulting and
custom software solutions to specifically meet your
needs. |
