Objective of this project work is the investigation of the geometry of a heat exchanger. The main purpose of a heat exchanger is the exchange of heat between two fluids. Therefore, the final flow and temperature field shall be analyzed.
Heat exchangers are widely used in all sorts of engineering purposes. One of the most known examples for the use of a heat exchanger is found in an engine. Engines run optimal at a certain temperature. This is where the heat exchanger comes into play. Engine coolant is pumped through canals in the engine and transports the built-up heat away. This liquid is warmer now and must be cooled down again. It therefore goes through the heat exchanger, where the relatively cold air from the environment flows past the coils with the liquid and cools the engine coolant. The cycle repeats itself as long as the engine is running.
The procedure is as follows. First, the creation of the geometry will be explained. Then the meshes shall be analyzed based on a description of the quality, grid convergence study and the energy balances between the heat fluxes. After an optimal mesh for further investigation has been chosen, different turbulence models are going to be investigated on the basis of turbulence values, pressure loss and heat transfer coefficients, which will be compared to the flow filament theory. Then a final investigation will be done with the turbulence model with the best results. Thereby the most important flow values for inner as well as outer flow, radial temperature distribution and the specific cooling power of the heat exchanger will be discussed.
Table of Contents
- Introduction
- Creation of the Geometry and Mesh
- Geometry
- Mesh
- Grid study
- Grid convergence study
- Energy Balances
- Investigation of Turbulence Models
- Comparison of different Turbulence Models
- Flow Filament Theory
- Final Simulation
- Most important Flow Values
- Comparison to Flow Filament Theory
- Radial Temperature Distribution
- Specific Cooling Power
- Summary
Objectives and Key Themes
The main objective of this work is to simulate the flow and heat transfer in a heat exchanger using computational fluid dynamics (CFD). The simulation aims to investigate the influence of different turbulence models on the results and to compare these findings with the Flow Filament Theory. The study also focuses on analyzing the radial temperature distribution in the fluid and the specific cooling power of the heat exchanger.
- Application of CFD to simulate fluid flow and heat transfer in a heat exchanger
- Investigation of different turbulence models (e.g., SST, k-omega, EVT)
- Comparison of simulation results with the Flow Filament Theory
- Analysis of the radial temperature distribution in the fluid
- Determination of the specific cooling power of the heat exchanger
Chapter Summaries
- Introduction: This chapter provides a brief overview of the project, introducing the problem and the specific research question. It outlines the objectives of the work and the key themes that will be addressed.
- Creation of the Geometry and Mesh: This chapter details the process of creating the geometry and mesh for the CFD simulation. It explains the specific geometry used, including the dimensions of the heat exchanger, and the different mesh types used (e.g., coarse, medium, fine).
- Grid study: This chapter focuses on the grid convergence study, analyzing the impact of mesh refinement on the simulation results. It investigates how the pressure and temperature distributions are influenced by the mesh size and discusses the criteria used to determine the optimal mesh for the simulation.
- Investigation of Turbulence Models: This chapter explores the effects of using different turbulence models on the simulation results. It compares the performance of various models (e.g., SST, k-omega, EVT) and analyzes their impact on the turbulent kinetic energy, viscosity, and other relevant parameters.
- Final Simulation: This chapter presents the results of the final simulation, using the chosen turbulence model and mesh. It analyzes the flow velocity, pressure, and temperature distributions in both the air and water. The chapter also examines the streamlines, the separation of the air flow, and compares the simulation results with the Flow Filament Theory.
Keywords
The main keywords and focus topics of this work include computational fluid dynamics (CFD), heat exchanger, turbulence models, grid convergence study, Flow Filament Theory, radial temperature distribution, specific cooling power, air flow, water flow, pressure distribution, temperature distribution, simulation analysis, engineering.
Frequently Asked Questions
What is the main objective of this CFD project?
The project aims to investigate the geometry of a heat exchanger by simulating fluid flow and temperature fields using Computational Fluid Dynamics (CFD).
What is a grid convergence study?
It is an analysis used to determine how the refinement of the simulation mesh (grid) affects the results. The goal is to find an optimal mesh size where results are no longer dependent on the grid density.
Which turbulence models are investigated in this study?
The study investigates different models such as SST (Shear Stress Transport), k-omega, and EVT to see which provides the most accurate results for pressure loss and heat transfer.
How is the simulation compared to the Flow Filament Theory?
The Flow Filament Theory serves as a theoretical benchmark. Simulation results for heat transfer coefficients and flow values are compared against this theory to validate the CFD model's accuracy.
What does "specific cooling power" represent in this context?
Specific cooling power refers to the efficiency of the heat exchanger in removing heat from one fluid (like engine coolant) to another (like environmental air) based on the geometry and flow rates.
Why is the radial temperature distribution important?
Analyzing the radial temperature distribution helps in understanding how heat is distributed across the cross-section of the heat exchanger tubes, which is crucial for optimizing heat transfer efficiency.
- Quote paper
- Benno Schönstein (Author), 2021, The Geometry of a Heat Exchanger (CFD/Flow Simulation), Munich, GRIN Verlag, https://www.grin.com/document/1156507
