Engines and Power Cycles, Turbomachinery and Secondary Flows


Turbomachine Components

System-level analysis of jet and rocket engines, power generation cycles, heat pumps and refrigeration loops, etc. can be made 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 parametric inputs, 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.

Validation Case

Advanced Liquid Oxygen Turbopump

Additional CRTech Resources

FloCAD online training

Class times: May 2 & 4 from 10am to 2pm MT

Cost: $425

This online class will provide an introduction to fluid modeling components within FloCAD. The class will be held over a 2-day period, with daily sessions running approximately 4 hours each. The class uses a mixture of lecture, demonstrations, and self-paced tutorials to allow attendees to practice building fluid system models and interpreting results. The presentations will comprise 2 - 3 hours of each session, and the instructor will be available during the remainder of the time for questions during tutorials. Attendees must have basic working knowledge of SINDA and Thermal Desktop as these topics will not be covered but their usage is required for FloCAD.

Register here

Thermal Desktop, RadCAD, and TD Direct in-class training

Date: April 25-28, 2017, 8:00 a.m. to 5:00 p.m., daily
Location: Lakewood, CO

CRTech will be hosting introductory training for Thermal Desktop, RadCAD and TD Direct. Lecture and hands-on tutorials introduce attendees to basic Thermal Desktop and RadCAD usage and allow practice building models and interpreting results. The class will also introduce students to SpaceClaim direct modeling CAD interface and advanced meshing tools in TD Direct.

Daily Schedule

Day 1 and 2: Introduction to SINDA and Thermal Desktop
Day 3: Introduction to RadCAD
Day 4: Introduction to TD Direct

To learn more about this class and to register, visit our Training Page.

Anode and cathode of a flow battery

Using Sinaps? It is not too soon to get started with TD/FloCAD!

This webinar describes the process for converting from Sinaps to Thermal Desktop (TD) and FloCAD. This process includes using an exporter which works with Version 6.0 of the CRTech tool suite (expected to be released in May of 2017).

Come learn about the basics of TD/FloCAD, including many compelling features not available in Sinaps. The webinar will also cover how to manage the transition period, during which you may be using both programs simultaneously. This is also a chance to ask questions. 

If you missed this webinar, please contact us for the presentation material and recording.