Flownex

Flownex SE ® determines pressure drop (flow) and heat transfer for the connected components of a complete system in steady state and transient, e.g. pumps or compressors, pipes, valves, tanks, and heat exchanges.

Flownex SE ® is the leading software of its kind in Turbo-manufacturing, Nuclear and Fossil Fuel Power and SMR industrials, partnering with the leading OME design and analysis . Additionally we have strong applications in the following sectors:

ACADEMIC; AEROSPACE; FOSSIL FUEL POWER; GAS PROCESSING; HEAT RECOVERY STEAM GENERATOR; H-VAC; INDUSTRIAL PROCESS; MINING; NUCLEAR POWER; OIL & PETROCHEMICAL; RESEARCH & DEVELOPMENT (CONSULTING); SMALL MODULAR NUCLEAR REACTOR; TURBINES...
 

Ansys Integration

1D system simulation software packages are easy to use and have fast solving times however, they don't always contain all the features needed in system simulations. 3D CFD packages become necessary in systems with components that contain complex 3D flow geometry that cannot be characterised in one dimension or in systems where three dimensional flow results are required. However, simulating an entire system in 3D is often incredibly computationally expensive and a hybrid 1D-3D simulation is ideal. Flownex can linked directly with other components in Workbench which allows users to run co-simulations where Flownex and any Ansys fluid dynamics tool (Ansys Fluent, Ansys CFX, etc.) can solve the 1D and 3D flows respectively and exchange information at the boundaries. This functionality provides the best of both worlds with reduced solving times due to the majority of the system being solved in Flownex while also containing the high detail and accuracy of a 3D fluid dynamics simulation. Flownex also adds value to structural simulations and can be used to transfer 1D flow results to a FEA simulation package such as Ansys Mechanical.

One application of the Fluent coupling is the simulation of the HVAC system in a server room. In this case Flownex was used to simulate the fan, heat exchanger and ducting to the server room while Fluent was used to simulate the heating of the air by the electronics and the air flow in the room. The interface points were chosen as the vents that supply air to the room where the temperature and flow results from Flownex were transferred to Fluent and the backpressure results from Fluent were transferred to Flownex. In this simulation control elements were added to the Flownex model to adjust the fan speed and the vent openings and the transient operation of the system was studied.

The Ansys Mechanical coupling has uses in many industries. An example as seen above is modelling the temperature distribution in an engine block. Flownex is used to model the heat transfer from the combustion gases and the water cooling flow through the block, Fluent is then used to model the conduction heat transfer in the engine block. The remainder of the engine cooling system, including the radiator, hoses and water pump are also modelled in Flownex and are adjusted until suitable engine block temperatures are achieved.

Another example of the Ansys Mechanical coupling is in the power generation industry. The example seen below shows a model of a boiler where the flows are calculated using Flownex and the thermal stresses are calculated using Ansys Mechanical. Using this analysis technique startup conditions can be simulated in a transient environment and boiler designs modified to ensure the stresses are all within allowable limits before construction begins.

Flownex is frequently used for the preliminary and concept design of thermal-fluid plant components. The key driver for using Flownex is resultant cost savings on account of reduced 3D CFD modelling requirements and rig tests. Additionally Flownex is used to provide boundary conditions for more detailed localised models Flownex and Ansys Fluent and Mechanical have proved to be powerful simulation tools. By coupling these software packages, simulations can be optimised for accuracy and solving time providing engineers with a robust set of simulation tools that can meet industry demands.
 

Gas Turbine Sector

Flownex Simulation Environment is the leading software in gas turbine integrated system design, making it easier to determine flow, pressure drop, heat- and work transfer for the connected Components of the complete gas turbine engine during both steady-state as well as transient events. Typical Flownex solutions in both the industrial and aerospace gas turbine sectors include combustor design, secondary flow analysis and overall system integration.

Preliminary combustor design requires that an extensive number of geometrical and operational conditions be evaluated and compared. Especially during this phase Flownex is an essential tool for combustor design engineers as it accurately captures important parameters such as the mass flow rate distribution through air admission holes, product gas composition and radiation, convection and conduction heat transfer, thereby predicting liner wall temperatures. Networks can be easily configured and solves within a few seconds. This result in substantial development cost savings because of the reduction in the number of detailed 3D simulations and rig tests required. A further advantage is the ability to use the Flownex results as boundary conditions in subsequent localized 3D models.

Flownex boasts a comprehensive rotating component flow library for analysing the coolant rotational flow field inside the gas turbine engine, also referred to as the secondary air system. Through application of the Flownex swirl solver, angular momentum transfer, windage power, heat transfer as well as pressure losses are accurately predicted throughout the secondary air system, featuring components such as stator-rotor and rotor-rotor cavities, rotating channels and orifices, vortices and seals. The Flownex flow network approach leads to much faster and more cost-effective baseline designs for these systems, since the number of expensive, detailed simulations are minimized.

Flownex furthermore allows engineers to investigate overall engine performance such as expansion thrust calculations, compressor surge margin calculations and perform power matching between compressors and turbines. The dynamic modelling capability further extends Flownex's usefulness in integrated engine simulations, allowing for predicting engine performance of numerous transient events such as start-up, load changes and emergency situations.

Flownex integrate seamlessly with CFD and FEA codes for more localized results where required. The Flownex tool runs 1000's of simulations rapidly allowing for multiple scenario tests and operating modes and eliminates uncertainty around environmental conditions and manufacturing tolerances.
 

Additional Resources:

Flownex Introduction
Flownex Offers New Simulation Tools for Gas Turbine Systems
Certification
System Level Thermal-Fluid Flow Simulation Software