Short answer

When designing turbine components exposed to particulate matter, leverage CFD simulations to test geometric modifications that can reduce harmful deposition, but be mindful of potential localized increases in deposition.

Field: Modelling
Source: OhioLink ETD Center (Ohio Library and Information Network) (2010)
Method: Numerical simulation using Computational Fluid Dynamics (CFD) with an Euler-Lagrangian two-phase approach.
Evidence: Strong effect

Simulating particle deposition in turbine passages using an Euler-Lagrangian approach and a calibrated sticking model can accurately predict the impact of geometric modifications on ash accumulation. This modelling research insight is drawn from a 2010 study published in OhioLink ETD Center (Ohio Library and Information Network). Using Numerical simulation using computational fluid dynamics (cfd) with an euler-lagrangian two-phase approach., researchers explored how this design variable affects real-world outcomes. The key design takeaway: When designing turbine components exposed to particulate matter, leverage CFD simulations to test geometric modifications that can reduce harmful deposition, but be mindful of potential localized increases in deposition.

Study

ModellingHigh ImpactStrong effect

Computational Fluid Dynamics Predicts 18% Reduction in Coal Ash Deposition with Hub End Wall Geometry Modification

Simulating particle deposition in turbine passages using an Euler-Lagrangian approach and a calibrated sticking model can accurately predict the impact of geometric modifications on ash accumulation.

OhioLink ETD Center (Ohio Library and Information Network) · 2010

Key Findings

01The Euler-Lagrangian two-phase approach with the standard k- turbulence model and a critical impact velocity sticking model can accurately predict coal ash deposition locations and quantities.
02A 30-degree reduction in the hub end wall inlet angle to the axial direction resulted in an overall 18% decrease in deposition mass.
03While the modified geometry improved deposition near the hub wall and pressure surface, it led to a slight increase in deposition in the mid-span region of the turbine vane.

Application

Design takeaway

How to apply

Use CFD software to model the flow and particle behaviour in your design. Experiment with different geometric parameters and validate your findings against available experimental data or established physical principles.

Project actions

01When choosing simulation software, consider its capabilities for multi-phase flow and particle tracking.
02Ensure any empirical models used (like sticking models) are well-calibrated to relevant experimental data or are clearly stated as requiring further calibration.

Method & Evidence

AimTo simulate and quantify the deposition of coal ash on turbine nozzle guide vanes and evaluate the effectiveness of a specific hub end wall geometry modification in mitigating this deposition.

MethodNumerical simulation using Computational Fluid Dynamics (CFD) with an Euler-Lagrangian two-phase approach.

ProcedureA CFD model of a turbine passage was created using FLUENT software. The standard k- turbulence model was employed. Particle trajectories and deposition were predicted using a critical impact velocity sticking model, calibrated against experimental data. The model was validated against experimental results from a turbine rig. Finally, a modified hub end wall geometry was simulated to assess its impact on deposition.

ContextGas turbine engineering, specifically focusing on the first stage of a GE-E 3 turbine operating with coal ash.

Variables

IVHub end wall inlet angle to the axial.

DVDeposition mass on turbine nozzle guide vanes.

CVTurbulence model (standard k-), sticking model (critical impact velocity), turbine stage geometry (base case).

Strengths & Limitations

Strengths

+Validation against experimental data provides confidence in the simulation's accuracy.
+Quantification of the geometric modification's impact (18% reduction) offers clear design insights.

Limitations

The simulation is a model and may not perfectly represent real-world conditions. The accuracy depends heavily on the quality of the input data and the chosen models.

Reliability & validity

The study's validity is supported by comparison with experimental results. Reliability would depend on the reproducibility of the simulation setup and parameters.

Think critically

How might the observed increase in deposition in the mid-span region of the turbine vane due to the hub end wall modification impact the overall efficiency and lifespan of the turbine?

Design Principles

"Utilize validated computational models to predict and optimize designs for complex fluid-particle interactions, such as deposition, before physical prototyping."

This research demonstrates the power of computational modelling in understanding complex physical phenomena like ash deposition in gas turbines. By simulating these processes, designers can iteratively test and optimize designs for improved performance and longevity without costly physical prototypes.

What This Means for Your Design

Using computer simulations, researchers found that changing the shape of a part inside a turbine could reduce how much coal ash built up on it by 18%.

How to use in your project

1.Reference this study when using CFD to predict the performance or behaviour of a design element, especially when dealing with fluid dynamics or particulate matter.

Add to My Project

Quick Cite

Paragraph starter

Computational fluid dynamics (CFD) simulations, as demonstrated by Barker (2010) in the study of coal ash deposition on turbine vanes, offer a powerful method for predicting the impact of design modifications. Their research utilized an Euler-Lagrangian approach to simulate particle trajectories and deposition, successfully predicting an 18% reduction in ash mass through a specific hub end wall geometry change, highlighting the potential for CFD to inform design decisions aimed at mitigating performance degradation.

Source

OhioLink ETD Center (Ohio Library and Information Network)

Simulation of Coal Ash Deposition on Modern Turbine Nozzle Guide Vanes

journal · 2010

View source

Questions About This Research

What does the research say about computational fluid dynamics predicts 18% reduction in coal ash deposition with hub end wall geometry modification?: When designing turbine components exposed to particulate matter, leverage CFD simulations to test geometric modifications that can reduce harmful deposition, but be mindful of potential localized increases in deposition. Evidence: OhioLink ETD Center (Ohio Library and Information Network) (2010).
Why does "Computational Fluid Dynamics Predicts 18% Reduction in Coal Ash Deposition with Hub End Wall Geometry Modification" matter for design?: This research demonstrates the power of computational modelling in understanding complex physical phenomena like ash deposition in gas turbines. By simulating these processes, designers can iteratively test and optimize designs for improved performance and longevity without costly physical prototypes.
How can designers apply this research?: When designing turbine components exposed to particulate matter, leverage CFD simulations to test geometric modifications that can reduce harmful deposition, but be mindful of potential localized increases in deposition.
What were the main findings?: The Euler-Lagrangian two-phase approach with the standard k- turbulence model and a critical impact velocity sticking model can accurately predict coal ash deposition locations and quantities.. A 30-degree reduction in the hub end wall inlet angle to the axial direction resulted in an overall 18% decrease in deposition mass.. While the modified geometry improved deposition near the hub wall and pressure surface, it led to a slight increase in deposition in the mid-span region of the turbine vane.
What research method was used?: Numerical simulation using Computational Fluid Dynamics (CFD) with an Euler-Lagrangian two-phase approach..
How strong is the evidence?: Evidence strength is rated Strong effect, based on a 2010 journal from OhioLink ETD Center (Ohio Library and Information Network).
What should I do differently in my next project?: Use CFD software to model the flow and particle behaviour in your design. Experiment with different geometric parameters and validate your findings against available experimental data or established physical principles.
What are the limitations?: The study focused on a specific turbine stage and coal ash composition. The accuracy of the sticking models is dependent on calibration to experimental data, and the critical viscosity sticking model required further calibration.