ADT and Siemens have partnered to demonstrate a rapid, blank-page-to-concept design workflow for an emergency Micro Gas Turbine (MGT).
By coupling Siemens Simcenter Amesim with TURBOdesign Suite, the joint workflow dramatically accelerates development:
This highly integrated, end-to-end loop slashes complex turbomachinery development timelines from months to days.
The Challenge: Emergency Standby Power for Critical Infrastructure
System-Level Simulation & Cycle Matching in Simcenter Amesim
From Meanline to 3D Geometry: Inverse Design & Co-Simulation
Critical facilities like hospitals, data centers, and essential infrastructure cannot afford even momentary power interruptions. Hospitals must prioritise patient safety, life support systems, and keep the lights on during emergency operations. Data Centres need to maintain data integrity, business continuity and mitigate any financial impact that comes from grid interruptions. A concept that can be put to use to support these critical standby power generation requirements is a Micro Gas Turbine (MGT) emergency generator kit.
Advanced Design Technology (ADT) have partnered with Siemens Digital Industries Software to demonstrate going from a blank page to fully realised concept design within a self-contained design system.
Taking into account e critical facility power demands, desired uptime and operational constraints, system architecture & Component Selection and cross domain system modelling , whilst evaluating fuel consumption, emissions, and operational costs for different MGT configurations and mission profiles. The steps to this process can be summarised as:
In this blog we show how TURBOdesign Suite creates baseline radial compressor/turbine meanline designs along with performance maps exportable to Simcenter Amesim for system-level iteration. Then generates and optimises 3D radial compressor/turbine geometry.
Upstream of the detailed turbomachinery design, Siemens built the cycle and mission profile in Amesim to couple the micro gas turbine with other elements to obtain sizing requirements, analysis and system behaviour within seconds.
Figure 1: Siemens Amesim develops the entire MGT system and the mission profile
This duty point and basic size requirements are passed to TURBOdesign Pre. Which starts to calculate the ideal compressor. It places the centrifugal compressor design on the Cordier Line (the locus of best performing compressors when described in terms of specific speed and specific diameter).
Figure 2: TURBOdesign Pre inputs show where the proposed design lies on the Cordier line
In a couple of seconds the meanline design of the splittered compressor stage with a vaneless diffuser is created, including all dimensions, velocity triangles and loss and performance estimates.
Figure 3: TURBOdesign Pre instantly calculates the meanline design of the compressor
And crucially, TURBOdesign Pre creates the estimate compressor map - this is converted to SAE format and directly imported to Amesim so that the system simulation can project the turbomachinery performance on and off-design to the MGT mission profile.
Figure 4: TURBOdesign Pre provides the performance map of the compressor stage
The next step is to match a turbine stage to the compressor. So we require matching mass flow rate (provided by the compressor, plus combustion products, typically +5% of the compressor flow), matching rotor speed, approximate matching expansion ratio and the excess power that we want to draw from the turbine.
In this case, TURBOdesign Pre tells us that to derive the compressor requires 207.4 kW. As we want to send 100kW to the generator, we ask TURBOdesign Pre to find a radial inflow turbine that will generate 308 kW shaft power at these flow conditions. We can assume a turbine inlet total temperature of 700K - which is typical of such combustion systems into a non-cooled system.
Figure 5: TURBOdesign Pre run in scripted batch mode to produce a matched turbine stage for the target compressor with 100kW excess shaft power
Figure 6: TURBOdesign Pre generates the full description of the radial inflow turbine
TURBOdesign Pre matches the compressor to a vaneless, 13 blade 276mm OD turbine, with a predicted design point overall efficiency of 81%, at an expansion ratio of 2.21:1.
Figure 7: TURBOdesign Pre predicts the flow and efficiency characteristics for the matched turbine
Again the predicted maps can be exported to SAE format and used in the system prediction by Anesim.
As Siemens wanted a complete, end-to-end analysis of the full MGT performance, this requires the 3D blade shapes, and these are created using the 3D Inverse Solver TURBOdesign1. For more information on how this unique method unlocks the turbomachinery design process. See our previous blog: "Blade Loading, Inverse Design and Shape Parameterisation”.
Figure 8: 3D Inverse Design models can be exported in a variety of formats and for a variety of purposes (full or periodic solid models, fluid volume, spanwise curve sets). STEP, IGES, point strings etc.
It is the work of just a couple of hours to produce fully operable, efficient and manufacturable rotor designs for both compressor and turbine. The default, machine-aware, settings within TURBOdesign1 will get you pretty close to a final design within the first iteration. There are a number of manual and automatic design exploration methods that can be employed, including multi-objective multi-point optimisation and the use of Physics-Enhanced Machine Learning methods to discover the optimal blade shapes for a given range of operating conditions. For information on some of the optimisation methods used in TURBOdesign1 see our previous blog: “What is Reactive Response Surface”
One of the key strengths of TURBOdesign1 is its straightforward interface to downstream analysis codes. This means that once created, the 3D blade shapes can be easily exported as both
Blade passage fluid domains (for CFD analysis)
Full wheel solids (for FEA structural and vibrational analysis).
The fact that these two model types also exactly match means that Siemens could build out their co-simulation capability. That is the combined aero-thermal, structural and vibrational analysis of the complete stage - including rotor dynamics. In the latest version of Simcenter Star-CCM+ all of this analysis is contained within the one package (was previously partly done in CCM+ and partly in Nastran).
Figure 9: 2D view on the design space (left) and the surrogate model pareto front constructed in the highest performing region of the design space (right)
Siemens and ADT have demonstrated that the complete system level design and analysis of a blank-page concept can be realised and created at the highest level of detail and design. Covering everything from initial requirements to blade profiles and harmonic response. The workflow includes
System-level simulation tools
Gas turbine pre-sizing
Physics-led 3-dimensional blade design.
The 3D blade generation is rapid and fully integrated, allowing the complete range of aero-thermal, mechanical and rotor-dynamic co-simulation analyses.