This chapter reviews the general concepts of fluid-structure interaction (FSI), with a focus on thermal FSI. So, it is known as Thermal FSI.It discusses two overall methodologies for simulating thermal FSI cases: Intrinsic FSI and Extrinsic FSI.In the first approach, all calculations of the fluid and solid domains and the interaction between them are performed by the Fluent solver. For this purpose, the Structure model with enabling Thermal effects is used.In the second approach, the calculations of the fluid and solid domains are performed separately and individually by different solvers. Then, by defining data transfer, the solvers are coupled together. For this purpose, the Fluent solver is used to solve the fluid flow, and the Structural and Thermal solvers are used to solve the solid domain.

DescriptionIn this project, we present a simulation of an Exhaust Manifold under Thermal FSI via ANSYS software. We have modeled a simple exhaust manifold consisting of a fluid domain dedicated to the gas flow and a solid region as the manifold body surrounding the fluid zone.What is FSI?The gas flow is discharged through the exhaust manifold. So, the gas flow can expose a pressure load on the inner wall of the manifold. In such a condition, analysis of Fluid-Structure Interaction (FSI) becomes important. It means that both fluid and structural calculations are available.Why Thermal FSI?Hot gas flows throughout the exhaust manifold. So, it is expected that a thermal load will be imposed on the solid body. As a result, the focus is on the Thermal FSI. It means the solution data of fluid flow, structural, and thermal calculations are coupled.1-way or 2-way?First, the effect of the pressure and thermal loads of the gas flow on the inner wall of the exhaust manifold is analyzed. Next, the effect of the solid manifold structure, deformed or displaced, on the nearby gas flow is investigated. Hence, it is called Two-way FSI.MethodologyFor FSI simulations, we recommend two general methods: intrinsic FSI and extrinsic FSI. If the calculation of both the fluid and the structure is performed only in ANSYS Fluent, it is called Intrinsic FSI. Meanwhile, if the calculation process of the fluid and the structure is performed in different and individual solvers and then coupled with each other, it is referred to as Extrinsic FSI.Extrinsic FSI:In this project, we have used the external FSI method. We performed the structural analysis corresponding to the manifold solid body in the ANSYS Steady-State Thermal solver, while we performed the fluid analysis corresponding to the gas flow in the ANSYS Fluent (Fluid Flow) solver.System Coupling:The steady-state Thermal solver and the Fluent solver are defined separately in the ANSYS Workbench environment. Then, fluid and solid calculations are performed to obtain the solution data. In this case study, we consider the inner wall of the exhaust manifold as the fluid-structure interface to couple the calculations. Therefore, the data transfer between the fluid and structure solvers is defined by the System Coupling tool.How to define Data Transfer?In the coupling system, we define two Data Transfers. One is the data transfer in the form of Heat Flow from fluid to structural solver, and the other is the data transfer in the form of Temperature, from structural to fluid solver.ConclusionWe have investigated the results with two approaches: thermal fluid analysis (from Fluent) and thermal structural analysis (from steady-state Thermal).Thermal Fluid:We obtained the distribution of the temperature and heat flux of the airflow within the manifold exhaust, as well as the temperature and heat flux on the surface of the manifold’s internal wall. The results show that heat transfer occurs between the fluid flow and the structural body, such that the heat flux is lost from the hot stream adjacent to the inner wall of the manifold.Thermal Structural:We obtained the contours related to the temperature and heat flux distributions on the manifold structure body. The results show that heat transfer occurs between the fluid flow and the structural body, such that the heat flux is absorbed by the internal surface of the manifold body.

DescriptionIn this project, we present a simulation of a T-junction Pipe under Thermal FSI via ANSYS software. We have modeled a simple T-junction containing a main pipe and a branch, so that two streams with different temperatures would be mixed. The computational domain consists of a fluid zone dedicated to the streams and a solid region as the pipe body surrounding the fluid zone.What is FSI?Two fluid streams flow through the T-junction pipe. So, the fluid flow can expose a pressure load on the inner wall of the T-junction pipe. In such a condition, analysis of Fluid-Structure Interaction (FSI) becomes important. It means that both fluid and structural calculations are available.Why Thermal FSI?Two streams with different temperatures flow throughout the T-junction. So, it is expected that a thermal load will be imposed on the solid body. As a result, the focus is on the Thermal FSI. It means the solution data of fluid flow, structural, and thermal calculations are coupled.1-way or 2-way?Only the effect of the pressure and thermal loads of the flow on the inner wall of the T-junction pipe is analyzed; no need to consider the effect of the solid T-junction structure on the nearby flow. Hence, it is called One-way FSI.MethodologyFor FSI simulations, we recommend two general methods: intrinsic FSI and extrinsic FSI. If the calculation of both the fluid and the structure is performed only in ANSYS Fluent, it is called Intrinsic FSI. Meanwhile, if the calculation process of the fluid and the structure is performed in different and individual solvers and then coupled with each other, it is referred to as Extrinsic FSI.Extrinsic FSI:In this project, we have used the external FSI method. We performed the structural and thermal analysis corresponding to the T-junction solid body in the ANSYS Static Structural and ANSYS Steady-State Thermal solvers, respectively, while we performed the fluid analysis corresponding to the streams in the ANSYS Fluent (Fluid Flow) solver.How to use solvers?The static Structural solver, the steady-state Thermal solver, and the Fluent solver are defined separately in the ANSYS Workbench environment. Then, fluid and solid calculations are performed to obtain the solution data. In this case study, we consider the inner wall of the T-junction pipe as the fluid-structure interface to couple the calculations.How to couple solvers?Note that the data between the fluid and structural solvers is transferred directly. First, by Fluent calculation, the thermal data from the fluid flow is transmitted as input in the form of Temperature Load to the Thermal solver. Then, on one hand, by steady-state Thermal calculations, the thermal data in the form of Temperature Body Load from the thermal solver, and on the other hand, by Fluent calculations, the flow data in the form of Pressure Body Load are transmitted to the static Structural solver.ConclusionWe have investigated the results with three approaches: fluid analysis (from Fluent), thermal analysis (from steady-state Thermal), and structural analysis (from static Structural).Fluid:We obtained the distribution of the temperature and pressure of the water flowing within the T-junction, as well as the surface temperature and pressure on the internal wall of the T-junction.Thermal:We obtained the contours related to the temperature distributions on the T-junction structure body. The results show that heat transfer occurs between the fluid and the structure.Structural:We obtained the contours related to the total deformation and von Mises stress on the T-junction structure body. The results confirm that the T-junction body undergoes considerable deformation under pressure and thermal stresses.

DescriptionIn this project, we present a simulation of a Bent Pipe under Thermal FSI via ANSYS Fluent software. We have modeled a simple pipe containing two bends. The computational domain consists of a fluid zone dedicated to the water flow and a solid region as the pipe body surrounding the fluid zone.What is FSI?The water flows throughout the pipe with two elbows. So, the fluid flow can expose a pressure load on the inner wall of the pipe (especially in bend zones). In such a condition, analysis of Fluid-Structure Interaction (FSI) becomes important. It means that both fluid and structural calculations are available.Why Thermal FSI?The hot water flows throughout the bent pipe. So, it is expected that a thermal load will be imposed on the solid body. As a result, the focus is on the Thermal FSI. It means the solution data of fluid flow, structural, and thermal calculations are coupled.1-way or 2-way?First, the effect of the pressure and thermal loads of the flow on the inner wall of the pipe is analyzed. Next, the effect of the solid pipe structure, deformed or displaced, on the nearby flow is investigated. Hence, it is called Two-way FSI.MethodologyFor FSI simulations, we recommend two general methods: intrinsic FSI and extrinsic FSI. If the calculation of both the fluid and the structure is performed only in ANSYS Fluent, it is called Intrinsic FSI. Meanwhile, if the calculation process of the fluid and the structure is performed in different and individual solvers and then coupled with each other, it is referred to as Extrinsic FSI.Intrinsic FSI:In this project, we have used the intrinsic FSI method. We performed fluid and solid analyses for both the fluid and structural domains, using only the ANSYS Fluent solver. It means that no external solver is required for the interaction between the fluid and the structure.Structure Model:For the internal FSI, we have used the Structure model. By this option, the calculations for solids are also added to fluids.Linear or Non-linear Elasticity?We used the Linear Elasticity method for structural analysis. It means that the deformation or displacement of the structure is proportional to the force value exerted by the fluid.Comparison analysis:To investigate the importance of thermal FSI, we carried out this project in two steps:In the first simulation, we ignored the energy equation and heat transfer and focused only on the hydraulic force of the flow.In the second simulation, we enabled the energy equation and heat transfer so that thermal loads were also included in the FSI analysis.Thermal Effect:Therefore, in the thermal FSI simulation, since we intend to analyze the thermal load in addition to the overall pressure load, we need to enable the Thermal Effect option.Why Dynamic Mesh?Since we have been using two-way FSI, the deformed structure can affect the behavior of the fluid flowing near it. So we need to also consider the deformation of the fluid domain over time. Therefore, we used the Dynamic Mesh tool. By this, we can define the interface between the fluid and the structure for coupling purposes.ConclusionWe have investigated the results by analyzing the interaction between fluid and solid.Comparison:We aim to represent a comparative analysis between the FSI due to the fluid pressure load and the FSI affected by both the pressure and thermal load.So, we obtained the contour corresponding to the distribution of the total displacement and von Mises stress. These contours are both for the inner wall of the pipe, which is exposed to the fluid flow, and for the outer wall of the pipe, which is freely movable.The results show that the maximum displacement appears in the bends or elbows of the pipe. This confirms that these regions undergo the highest deformation due to the fluid flowing.In addition, the stress is considerable near bends and elbows. However, since the two ends of the pipe are considered as fixed supports, the highest stress is shown.

DescriptionIn this project, we present a simulation of a T-junction Pipe under Thermal FSI via ANSYS Fluent software. We have modeled a simple T-junction containing a main pipe and a branch, so that two streams with different temperatures would be mixed. The computational domain consists of a fluid zone dedicated to the streams and a solid region as the pipe body surrounding the fluid zone.What is FSI?Two fluid streams flow through the T-junction pipe. So, the fluid flow can expose a pressure load on the inner wall of the T-junction pipe. In such a condition, analysis of Fluid-Structure Interaction (FSI) becomes important. It means that both fluid and structural calculations are available.Why Thermal FSI?Two streams with different temperatures flow throughout the T-junction. So, it is expected that a thermal load will be imposed on the solid body. As a result, the focus is on the Thermal FSI. It means the solution data of fluid flow, structural, and thermal calculations are coupled.1-way or 2-way?First, the effect of the pressure and thermal loads of the flow on the inner wall of the T-junction pipe is analyzed. Next, the effect of the solid T-junction structure, deformed or displaced, on the nearby flow is investigated. Hence, it is called Two-way FSI.MethodologyFor FSI simulations, we recommend two general methods: intrinsic FSI and extrinsic FSI. If the calculation of both the fluid and the structure is performed only in ANSYS Fluent, it is called Intrinsic FSI. Meanwhile, if the calculation process of the fluid and the structure is performed in different and individual solvers and then coupled with each other, it is referred to as Extrinsic FSI.Intrinsic FSI:In this project, we have used the intrinsic FSI method. We performed fluid and solid analyses for both the fluid and structural domains, using only the ANSYS Fluent solver. It means that no external solver is required for the interaction between the fluid and the structure.Structure Model:For the internal FSI, we have used the Structure model. By this option, the calculations for solids are also added to fluids.Linear or Non-linear Elasticity?We used the Linear Elasticity method for structural analysis. It means that the deformation or displacement of the structure is proportional to the force value exerted by the fluid.Thermal Effect:Since we intend to analyze the thermal load in addition to the overall pressure load, we enable the Thermal Effect option.Why Dynamic Mesh?Since we have been using two-way FSI, the deformed structure can affect the behavior of the fluid flowing near it. So we need to also consider the deformation of the fluid domain over time. Therefore, we used the Dynamic Mesh tool. By this, we can define the interface between the fluid and the structure for coupling purposes.ConclusionWe have investigated the results by analyzing the interaction between fluid and solid.Structural:We obtained the contours related to the distribution of the total displacement and von Mises stress on the T-junction structure body (both for the inner wall of the pipe, which is exposed to the fluid flow, and for the outer wall, which is freely movable.The results confirm that the maximum displacement appears in the T-junction zone, between the fixed support at the end of each branch. It means that T-junction regions undergo the highest deformation due to the fluid flowing.On the other hand, the stress reaches its highest value at the adjacent to each support. In addition, the branch containing the hotter fluid shows a higher stress, which could be due to the effect of thermal stress.

DescriptionIn this project, we present a simulation of a Gas Turbine Blade under Thermal FSI via ANSYS Fluent software. We have modeled a single blade from one of the stages of a gas turbine, which contains an internal channel with fine holes for the cooling process. The computational domain consists of a fluid zone dedicated to the streams and a solid region as the pipe body surrounding the fluid zone.What is FSI?Air flows throughout the turbine blade construction and through its holes. So, the fluid flow can expose a pressure load on the inner wall of the T-junction pipe. In such a condition, analysis of Fluid-Structure Interaction (FSI) becomes important. It means that both fluid and structural calculations are available.Why Thermal FSI?The cooling airflow inside the turbine's internal channel is in contact with the hot body of the turbine blade. So, it is expected that a thermal load will be imposed on the solid body. As a result, the focus is on the Thermal FSI. It means the solution data of fluid flow, structural, and thermal calculations are coupled.1-way or 2-way?Only the effect of the pressure and thermal loads of the flow on the inner wall of the turbine blade is analyzed; no need to consider the effect of the solid blade structure on the nearby flow. Hence, it is called One-way FSI.MethodologyFor FSI simulations, we recommend two general methods: intrinsic FSI and extrinsic FSI. If the calculation of both the fluid and the structure is performed only in ANSYS Fluent, it is called Intrinsic FSI. Meanwhile, if the calculation process of the fluid and the structure is performed in different and individual solvers and then coupled with each other, it is referred to as Extrinsic FSI.Intrinsic FSI:In this project, we have used the intrinsic FSI method. We performed fluid and solid analyses for both the fluid and structural domains, using only the ANSYS Fluent solver. It means that no external solver is required for the interaction between the fluid and the structure.Structure Model:For the internal FSI, we have used the Structure model. By this option, the calculations for solids are also added to fluids.Linear or Non-linear Elasticity?We used the Linear Elasticity method for structural analysis. It means that the deformation or displacement of the structure is proportional to the force value exerted by the fluid.Thermal Effect:Since we intend to analyze the thermal load in addition to the overall pressure load, we enable the Thermal Effect option.ConclusionWe have investigated the results by analyzing the interaction between fluid and solid.Structural:We obtained the contours related to the distribution of the total displacement and von Mises stress on the inner wall of the turbine blade (interface between fluid and solid zones), which is exposed to the cooling flow.The results confirm that the maximum deformation and stress are concentrated in the upper zones of the blade, because the fixed support is defined on the central turbine body. In addition, since the upper regions of the gas turbine blade are exposed to the minimum values of the internal cooling process, the highest thermal stress may appear.