Two Phase Flow Regimes

THEME: Root Cause Analysis of System Performance Anomalies 

This case study ‘Two-Phase Flow Regimes’, aims to demonstrate the capability of Flownex SE to carry out root cause analysis of a system to determine the cause of a system performance and safety issue. In addition to identifying the underlying cause, using Flownex SE it is possible to deliver an optimized design solution in the simulation model, in order to remove the root cause issue and generate an improved design configuration.

The case study presents how Flownex SE was successfully employed in a Power Plant commissioning project where it quickly identified the cause of a system performance anomaly, optimized the system design to remove the anomaly and efficiently returned the system performance back within desired performance parameters.

One of the considerable benefits aside from identifying and rectifying the design issue was that by using Flownex SE the analysis and optimization study was executed quickly and cost effectively keeping the commissioning schedule on track and mitigating the commercial impact on the project.

Open case study

Generator Seal Oil System

THEME: Failure Mode Analysis of Thermo Hydraulic Machine Components 

This case study ‘Generator Seal Oil System’, aims to demonstrate the capability of Flownex SE to simulate thermo hydraulic machine system components such as seals and simulate operational scenarios to test limits of the machine component to determine the failure modes and effects analysis of the component, to gain better understanding of how the system behaves and works. 

This case study presents how Flownex SE was successfully employed to model a power generation unit hydrogen seal ring and determine causes of seal failure leading to system trips. The Flownex simulation model clearly demonstrated the relationships between system pressure, seal clearances and turbine speeds.

One of the main benefits of modelling the system to determine failure modes and causes was the saving realised by being about to perform this investigative study in the simulation environment. In order to conduct an inspection and investigation in the plant after a trip the machine is shut down and the time required for cool down, stripping, inspection and restarting is considerably costly. This simulation study quickly highlighted the out of specification issue causing the system trips allowing the client to confidently take remedial action to eliminate the issue causing the system trips. 

Open case study

Dynamic Mid-Air Refueling

Perform critical analysis of failure cases during dynamic mid-air refueling of a Mirage F1 Fighter. Flownex allowed engineers to simulate flow rates and the refueling sequences of the system. Track fuel distribution and investigate valve failure cases. The simulations ensured that, for any single failure case, the system would remain safe and ensure the center-of-gravity (cg) position of the aircraft remained centered. Aerosud confirmed results predicted by Flownex with ground test results.  The simulation provided Aerosud with the confidence of delivering a final system design that is safe, reliable and conforms to customer requirements.

Open Case study


Flow measurement orifice plate sizing and uncertainty analysis

This case study demonstrates the use of some of Flownex’s power features – the Designer and the Sensitivity Analysis capability – during the design and uncertainty evaluation of flow measurement using an orifice plate connected to a pressure transducer and transmitter. 

Challenge: The main challenge for this case study is the application of Flownex to: 

  • Size an orifice plate to be used in conjunction with a flow transmitter to serve as an accurate flow meter for natural gas. 
  • Evaluate the measurement uncertainty of the flow meter with variations in operating conditions and manufacturing tolerances. 

Benefits: Flownex is an ideal tool to design gas flow systems, including piping, valving and most other components that are typically found in the oil and gas industry. Not only is Flownex also the ideal tool to design accurate flow measurement orifice plates, but it also has the capability to evaluate the uncertainty of the flow meter in general and the orifice plate in particular with the inevitable variations in conditions and manufacturing tolerances. 

Solution: Using the Designer and the Sensitivity Analysis features built into Flownex, the orifice plate can be designed and its operational uncertainty evaluated when functioning in combination with the pressure transducer/flow transmitter. 

Open case study

Coalescing filter sizing and life cycle analysis using rated and specified pressure loss components

This case study discusses the sizing of a coalescer filter and demonstrates its fouling life cycle analysis using a Flownex® model which implements two new pressure loss components: 

  • A rated pressure loss component. 
  • A specified pressure loss component. 

Challenge: The main challenge is the sizing and life cycle analysis of a typical coalescing filter. To simplify the Flownex model and assist with the analysis of the system performance, two new pressure loss components have been developed and are also presented in this case study. 

Benefits: Although not overly complicated, the design and lifecycle analysis of a filter system has a few interesting aspects that need to be highlighted. The two new components specifically developed to assist with this analysis should prove useful to other Flownex users by simplifying the specification of typical pressure losses in complex networks. 

Solution: A complete filter life cycle analysis is presented which may be applied to other similar filtration systems in Flownex networks. Two simple compound components have been developed and are discussed and demonstrated in this case study. 

Open case study

A basic immersion firetube Flownex model

This case study demonstrates the implementation of a basic immersion firetube model in Flownex and presents natural draft and forced draft examples.

Challenge: The main challenge is to model an immersion firetube in Flownex. Immersion firetubes are widely used in industry, most commonly in indirect heating applications where either gas or oil burners are used as a heat source.

Benefits: Flownex allows the user to model combustion, heat transfer and fluid flow processes in an elegant and easy to understand way.

Solution: Using Flownex’s compound component and scripting capabilities, a simple immersion firetube model has been developed and is presented in this case study. Furthermore, examples of natural draft and forced draft design cases are presented.

Open case study

Pebble Bed Micro Model

The case study demonstrates a load following transient simulation of the Pebble Bed Micro model (PBMM).

Open case study

Pebble Bed Micro Model Start-up

The PBMM (the world's first closed cycle multi-shaft gas turbine test rig) was developed to demonstrate the operation of a three-shaft, pre- and inter-cooled recuperative Brayton cycle in order to gain a better understanding of its dynamic behavior. The entire cycle was designed, simulated and commissioned with Flownex within 9 months at a cost saving of $48 million.

Open case study

HTGR Power cycle

This case study demonstrates the steady-state simulation of a High Temperature Gas-Cooled Reactor (HTGR) nuclear power plant (NPP). The HTGR is one of the most promising reactor concepts of the Nuclear Renaissance, offering advantages such as improved safety and economics, shorter construction times, distributed generation and high temperature availability for process heat applications such as hydrogen production.

Open case study

Design Optimization

CASE STUDY: Styldrift Mine Air Reticulation System

Challenge: This case study ‘Styldrift Mine’, aims to demonstrate the capability of Flownex SE to create an accurate simulation model to carry out a design optimization study of a large compressed air network. To determine the ideal design with regard to sizing pipes, accumulators, compressor equipment and future expansion accounting for total equipment consumption and factored losses in the system.

The case study presents how Flownex SE was successfully employed on a large mining installation design project, where it successfully determined the operating conditions of a proposed installation to deliver an optimized final design. The case study describes how using a step by step approach in Flownex through a series of simulations the user can improve operational performance, test every possible demand load scenario. This shows that Flownex is not just a thermo fluids analysis tool, but it can also be used in the mechanical design optimization of thermo fluid systems in the mining industry.

One of the considerable benefits aside from delivering an optimized design on this project was the fact that the detailed mechanical design can be based on the Flownex optimum design recommendations. Thereby reducing the additional project and operational costs usually associated with over or under specification of equipment when an optimized design has not been fully simulated, tested and determined.

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