CFD Simulation Tool Research Articles

Determination of the Gas Plenum Temperature of the P2M Instrumented Fuel Rodlets on the Basis of a Thermal-Hydraulic Study of the Belgian Reactor 2 Pressurized Water Capsule

To refine knowledge about pressurized water reactor fuel melting, the Power to Melt and Maneuverability (P2M) project in the Framework for Irradiation Experiments II (FIDES-II) managed by the Nuclear Energy Agency of the Organisation for Economic Co-operation and Development aims to perform two irradiation tests to reach fuel centerline partial melting using instrumented experimental fuel rodlets irradiated in a pressurized water capsule (PWC) of the Belgian Reactor 2 (BR2) [Studiecentrum voor Kernenergie (SCK CEN), Belgium]. Prior to these experiments, two preliminary tests will be performed in the PWC for qualification purpose toward safety. The experimental rodlets will be instrumented with a fuel centerline thermocouple in the lower part of the fuel and a pressure sensor (PS) in the upper part. An objective of the P2M experiments is to determine the amount of fission gas released from the fuel thanks to the PS measurement. The plenum pressure evolution is known from the measurement, and knowledge of the gas plenum temperature is required to determine the amount of fission gas released from the fuel to the plenum. The gas plenum temperature will depend on natural convection of the PWC coolant, and no temperature measurement will be possible within this gap during the test. This paper describes the setting up of a model of the BR2 PWC equipped with the P2M rodlets based on the coupled NEPTUNE_CFD (multiphase fluid calculation code) and SYRTHES (solid thermal module) simulation tools. Simulations performed thanks to this model allow assessment of the thermal-hydraulic (TH) behavior of the pressurized water in the capsule and the thermal behavior of the rodlet, in particular, regarding the temperature of the gas located in the plenum. For consistency of the results, computations presented in this paper were performed using a single and consistent set of TH models. A mesh sensitivity analysis was carried out for all the studied cases. Simulation results related to the water capsule behavior were found to be in good agreement with the available experimental data. The gas plenum temperature results obtained from this study will be used to assess the fission gas release during the test from the plenum pressure measurements. Overall experimental validation of fission gas release during the test will be possible after the transient test in BR2 based on the postirradiation examination program foreseen on the rodlets at the LECA-STAR facility [Commissariat à l’énergie atomique et aux énergies alternatives (CEA) Cadarache, France].

Blood Flow Simulation of Aneurysmatic and Sane Thoracic Aorta Using OpenFOAM CFD Software

Cardiovascular diseases still represent one of the most deadly pathologies worldwide. Knowledge of the blood flow dynamics within the cardio-vascular system is crucial in preventing these diseases and analysing their physiology and physio-pathology. CFD simulations are highly effective in guiding clinical predictions and, more importantly, allow the evaluation of physical and clinical parameters that are difficult to measure with common diagnostic techniques. Therefore, in particular, this study is focused on investigating the hemodynamics of the thoracic aorta. Real aortic geometries regarding a sane and diseased patient presenting an aneurysm were considered. CFD simulations were performed with the OpenFOAM C++ library using patient-specific pulsatile blood flow waveforms and implementing the Windkessel pressure boundary condition for the artery outflow. The adopted methodology was preliminarily verified for assessing the numerical uncertainty and convergence. Then, the CFD results were evaluated against experimental data concerning pressure and velocity of the thoracic aorta measured with standard diagnostic techniques. The normal aorta’s blood flow was also compared against the pattern regarding the patient-specific aortic aneurysm. Parameters such as wall pressure, wall shear stress (WSS) and velocity distribution were investigated and discussed. The research highlighted that the blood flow in the aorta is strongly affected by the aneurysm onset, with the growth of recirculation zones being potentially hazardous. The outcomes of the investigation finally demonstrate how CFD simulation tools, capturing the detailed physics of the aortic flow, are powerful tools for supporting clinical activities of the cardio-vascular system.

Detailed description of the flow fields induced by a fire in a mechanically-ventilated compartment obtained using PIV

This study analyses the performance of non-intrusive PIV (Particle Image Velocimetry) for the study of flows induced during a fire scenario in a mechanically-ventilated enclosure. PIV can be used to obtain detailed measurements for velocity fields in the enclosure and thus offer new experimental data for the understanding of the physical phenomena involved as well as to validate CFD simulation tools. The study is carried out on a reduced scale on an ethanol pool fire positioned in a ventilated enclosure. Several areas of interest are studied such as interaction between the fire plume and the ceiling, the flow under the ceiling and parietal flows. These zones can be analysed to obtain a picture of the global mean flow and associated velocity fields rarely reported in the literature. The influence of the fire heat release rate on the velocity fields is studied and highlights the design parameters.

Complete Workflow of Internal Nozzle Flow and Engine Simulation Using Multi-Component Fuel at Flash Boiling Conditions

Article Complete Workflow of Internal Nozzle Flow and Engine Simulation Using Multi-Component Fuel at Flash Boiling Conditions Bejoy Mandumpala Devassy 1, Yidan Zhang 2, * , Enyuan Zhang 2, and Long Zhou 2 1 AVL LIST GmbH, Hans-List-Platz 1, Graz 8020, Austria 2 AVL List Technical Center (Shanghai) Co., LTD. Shanghai 201206, China * Correspondence: yidan.zhang@avl.com Received: 17 May 2023 Accepted: 1 September 2023 Published: 14 September 2023 Abstract: At present 3D CFD simulation tools are getting more and more importance for addressing complex physical problems. This article presents a complete virtual analysis of the in-cylinder workflow in gasoline engine at flash boiling condition. Using the standard gasoline surrogate fuel PACE-20, properties of different fuel components was considered both the nozzle and in-cylinder flow. The flow, evaporation, spray jet interaction and spray collapse under flash boiling condition was studied. Molar density fraction was used to describe fuel component distribution for both gas phase and liquid phase. Based on nozzle flow simulation result, in-cylinder simulation has been done, the distribution of different fuel components and the influence on wall film, flame propagation, emission distribution has been studied. It shows that the simulation results have good agreement with testing data, and it proves the model validation for gasoline engine virtual development method under flash boiling conditions.

A novel layout to charge a single cylinder diesel engine using supercharging and impulse turbo-compounding

The benefits of turbocharged internal combustion engines are well established in the literature and mass production. Despite the numerous advantages of turbocharging, commercial single-cylinder engines are generally not turbocharged. This is due to intermittent exhaust gas flow to the turbine, typical for a single-cylinder engine. The current work proposes a novel layout wherein a supercharger boosts the engine to reap the benefits of charging the single-cylinder engine. An impulse turbine salvages part of the exhaust energy from the pulsated flow. A one-dimensional simulation study of the novel supercharged and turbo-compounded single-cylinder engine was carried out, and critical parameters of an impulse turbine were designed. CFD simulation study was carried out to validate the performance of the impulse turbine and the novel layout. This study modified a light-duty naturally aspirated (NA) diesel engine currently in mass production into the supercharged version. A positive displacement supercharger was mechanically coupled to the base NA engine with a suitable belt drive, and steady-state experiments were performed with NA and supercharged versions. One-dimensional AVL boost simulation models were validated for the NA and supercharged engines for brake power, air flow rate and BSFC within a 3% deviation. Nozzles of varying exit diameters were employed at the exhaust pipe. One-dimensional simulations were conducted to predict the supercharged engine performance and the kinetic energy rate available at the exhaust nozzle exit. An optimal nozzle exit diameter was chosen. Base calculations for the impulse turbine were performed with the output from the 1D simulation tool to design the critical features of the blade and the power turbine. The designed impulse turbine was further simulated using a commercially available CFD simulation tool, CONVERGE. CFD results showed that the impulse turbine generated about 1.55 kW of power, equivalent to 39% turbine efficiency. Experimental analysis was conducted on the supercharged engine with the optimal nozzle and the simulated impulse turbine. Results showed significantly improved engine performance with the supercharged and impulse turbine compounded version compared to the base NA version. The brake power output and brake thermal efficiency increased by 34% and 3.8%, respectively. Soot and carbon monoxide (CO) emissions were 80% lower, while unburned hydrocarbon (HC) emissions were 45% lower. However, NOx emissions were 60% higher, which can be curtailed by established NOx reduction strategies. Thus, the proposed method of employing a supercharger and compounding an impulse turbine for a single-cylinder diesel engine proved beneficial with improved performance, reduced brake specific fuel consumption and reduced emissions except for NOx.

CFD Modelling of the Interior Conditions of a Multipurpose Space

The article explores how CFD simulation tools can be applied to the design of central heating and air-conditioning systems in buildings. The models created with these tools can evaluate the thermal comfort conditions in the rooms, as well as the heat balance of the rooms. Thermal comfort is a key factor for the proper functioning of a building. It requires creating suitable thermal conditions indoors in both summer and winter. The article compares different heating ventilation and cooling methods using CFD.

The impacts of surface roughness on Indoor aerodynamics of virus-laden particles: The case of contact, deposition, and resuspension

The increasing prevalence and high morbidity of the SARS-CoV-2 virus during the COVID-19 pandemic drew widespread global attention. Surface contact is among the most common ways for the infection to spread within people, especially in buildings and the built environment. The roughness characteristics of finishing materials used in buildings vary, affecting the surface's ability to deposit and resuspend any particles that come into contact with these interfaces. Resuspension of particles indoors may increase the risk of consequent exposure through inhalation. However, little is known about surface roughness characteristics' role in airborne transmission of virus-laden particles in building indoor environments. The study examines the impact of surface roughness characteristics on the airborne transmission of the SARS-CoV-2 virus, considering indoor aerodynamic forces and their influence on particle contact with surfaces, deposition, and resuspension. The study applies Ansys Fluent CFD simulation tools to investigate the effect of volumetric flow rates and air velocity on concentration, deposition, and resuspension. The study also employs an empirical model to estimate surface roughness characteristics' impacts on particle resuspension rate. The results indicate that particle concentration and deposition rates indoors increase with increasing volumetric airflow rates. The particle resuspension rates also decreased with the increasing surface roughness of indoor surface materials. The highest resuspension rate recorded was 3.3 x 10-6, and the lowest was 1.6 x 10-6 s-1. Therefore, the outcome provides information on the implications of surface material selection and its effects on indoor air quality, health, and virus transmission. The study will offer valuable information for building engineering and design professionals in combating airborne disease transmission due to indoor surface characteristics.

CFD simulation-based predesign of an advanced gas-diesel combustion concept

The greenhouse gas saving potential of using gaseous fuels with high methane content (e.g. natural gas) in internal combustion engines instead of conventional liquid fossil fuels (e.g. petrol, diesel) is considerable due to the comparatively low emission of carbon dioxide resulting from the low C/H ratio of methane. However, to fully exploit this potential, it is of utmost importance to keep methane slip at a very low level. In contrast to mixture aspirated gas engines and diesel-gas engines, the gas-diesel combustion concept avoids methane slip nearly completely since the gaseous fuel is directly injected into the combustion chamber at the end of the high-pressure phase of the engine cycle, resulting in mixing-controlled combustion with low emission of unburned hydrocarbons. An advanced high-speed large engine concept based on the gas-diesel combustion process was developed. An effective and reliable virtual design methodology was applied during the development of the concept. The methodology comprehensively combines 3D CFD and 1D simulation tools in the combustion concept predesign phase with experiments on a single-cylinder research engine in the concept validation phase. A major challenge in the virtual design of this dual fuel combustion process is the large number of degrees of freedom that result in particular from the use of a fully flexible combined gas/diesel injector. This paper describes in detail the role of 3D CFD simulation in this approach, which allows precise prediction of the optimal geometries and operating strategies for high-efficiency and low-emission engine operation.

Investigation on the Aerodynamic Efficiency of Braking Spoiler for High Speed Train Applications

The demand for high speed rail networks is rapidly increasing in developing countries like India. One of the major constraints in the design and implementation of high speed train is the braking efficiency with minimum friction losses. Recently, the aerodynamic braking concept has received good attention and it has been incorporated for high speed bullet trains as a testing phase. The braking performance is extremely important to ensure the passenger safety specifically for the trains moving at more than 120[Formula: see text]km/h. In this paper, an Indian train configuration WAP7 (wide gauge AC electric passenger, Class 7) has been assumed with the locomotive and one passenger car. Aerodynamic braking system design is done by opening a spoiler over the train to amplify the aerodynamic drag at high speeds. The magnitude of braking force depends on the position and orientation of the braking spoiler. It creates differential drag forces at various deflection angles to decelerate the trains instantaneously in proportion to the running speeds. Drag created by the braking spoiler is observed numerically with the help of CFD simulation tools for further validation through wind tunnel experiments. Striking aerodynamic results are obtained with and without braking spoilers on the passenger cars and the spoiler at [Formula: see text] orientation makes greater drag coefficient as compared to the other angles.

CFD Simulation Based Investigation of Cavitation Dynamics during High Intensity Ultrasonic Treatment of A356

Ultrasonic treatment (UST) and its effects, primarily cavitation and acoustic streaming, are useful for a high range of industrial applications, e.g., welding, filtering, cleaning or emulsification. In the metallurgy and foundry industry, UST can be used to modify a material’s microstructure by treating metal in the liquid or semi-solid state. Cavitation (formation, pulsating growth and implosion of tiny bubbles) and its shock waves, released during the implosion of the cavitation bubbles, are able to break forming structures and thus refine them. In this context, especially aluminium alloys are in the focus of the investigations. Aluminium alloys, e.g., A356, have a significantly wide range of industrial applications in automotive, aerospace and machine engineering, and UST is an effective and comparatively clean technology for its treatment. In recent years, the efforts for simulating the complex mechanisms of UST are increasing, and approaches for computing the complex cavitation dynamics below the radiator during high intensity ultrasonic treatment have come up. In this study, the capabilities of the established CFD simulation tool FLOW-3D to simulate the formation and dynamics of acoustic cavitation in aluminium A356 are investigated. The achieved results demonstrate the basic capability of the software to calculate the above-mentioned effects. Thus, the investigated software provides a solid basis for further development and integration of numerical models into an established software environment and could promote the integration of the simulation of UST in industry.

Cavitation of a Submerged Jet at the Spherical Valve Plate/Cylinder Block Interface for Axial Piston Pump

The spherical valve plate/cylinder block pair has the advantages of strong overturning resistance and large bearing area. However, the configurations of the unloading and pre-boosting triangular grooves on the spherical valve plate are different from those in the planar valve plate, resulting in special cavitation phenomenon on the spherical port plate pair. In order to study cavitation characteristics of spherical port plate pair, a dynamic CFD model of the piston pump including turbulence model, cavitation model and fluid compressibility is established. A detailed UDF compilation scheme is provided for modelling of the micron-sized spherical oil film mesh, which makes up for the lack of research on the meshing of the spherical oil film. In this paper, using CFD simulation tools, from the perspectives of pressure field, velocity field and gas volume fraction change, a detailed analysis of the transient evolution of the submerged cavitation jet in a axial piston pump with spherical valve plate is carried out. The study indicates the movement direction of the cavitation cloud cluster through the cloud image and the velocity vector direction of the observation point. The sharp decrease of velocity and gas volume fraction indicates the collapse phenomenon of bubbles on the part wall surface. These discoveries verify the special erosion effect in case of the spherical valve plate/cylinder block pair. The submerged cavitation jet generated by the unloading triangular grooves distributed on the spherical valve plate not only cause denudation of the inner wall surface of the valve plate, but also cause strong impact and denudation on the lower surface of the cylinder body. Finally, the direction of the unloading triangular groove was modified to extend the distance between it and the wall surface which can effectively alleviate the erosion effect.

CFD Simulation of Local Scouring Around Bridge Pier

The threat of local scour around bridge piers has been in research for many years. According to the various studies, local scour around the bridge pier is the prime cause for most of the bridge failures. The main objective of the present study was to investigate the flow behavior and the scour phenomenon around the bridge piers of various shapes namely Circular, Elliptical, Square and Streamlined. Local scouring depends on various factors like depth of flow, upstream flow conditions, pier shape and dimensions. Here, we have taken only pier shape as the primary factor and kept other factors constant. The numerical simulations were even carried out using CFD- Fluent, Eulerian multiphase model, k–epsilon turbulence model, to elaborate the physics behind the scour formation. CFD simulation tool can be used for wide understanding of the flow behavior around the bridge piers even without physical model studies because it saves time and money as compared to experimental studies. Three dimensional simulation of flow behavior around four pier shapes indicates that the streamlined pier is the most efficient pier to use as it allows the flow to pass smoothly around it creating less obstruction to the flow and hence creating less chances of local scouring near the pier toe.

CFD studies for energy conservation in the HVAC system of a hatchback model passenger car

ABSTRACT Heating, Ventilation and Air Conditioning (HVAC) system of a passenger cabin in a vehicle is a largest auxiliary load in an automobile, apart from primary tractional load. A larger energy for HVAC system can reduce the driving range of an electric vehicle. The same condition may result in increase in fuel consumption of an engine-driven vehicle up to 25%. Excessive heating up of the passenger compartment is primarily caused by exposure of the vehicle to peak solar radiation. Energy conservation studies will reduce the energy consumption as well as initial size of cooling system. In the present work, the CFD analysis of a HVAC system in a hatchback car model has been carried out. The analysis was executed to find the baseload and temperature rise in an automobile passenger cabin without cooling. Following this, the cooling process has been implemented in the CFD model. Energy conservation measures, such as implementation of different types of insulation materials and window blinds have been carried out to study the temperature reduction by insulations and window blinds in the car cabin. The interior fluid domain of the car cabin has been modeled and simulated using ANSYS FLUENT 19.0 software. Results obtained from various simulations revealed the usefulness of the CFD simulation tool in studying the various parameters that are responsible for energy consumption in an automobile. The results taken from the simulation can be used by vehicle manufacturers for their vehicle advancement and they can develop a CFD model for optimizing the HVAC energy in an automobile.

Simulation of startup operation of an industrial twin-shaft gas turbine based on geometry and control logic

In this paper, a transient model is developed to simulate the start-up operation of an industrial twin-shaft gas turbine based on real geometry and control logic. The components’ characteristic curves of the studied gas turbine were generated with the aid of CFD simulation tools and according to the real geometry of each component. The control logic of the studied gas turbine was simplified and coupled with the developed engine performance model. Also, the gas turbine actuators including variable inlet guide vanes, compressor bleed valves, and fuel valves were simulated so that their concurrent effects on the gas turbine transient behavior can be captured precisely. Moreover, the air-cooled compressor turbine was modeled with a new approach. The integrated model was set up and then tuned with the field data in the base load condition. Next, the start-up operation of the gas turbine from zero speed to the base load condition was simulated and validated with the field data. The results show good agreement between the model outputs and field data. Regarding the model outputs, it can be used as the base code for a more comprehensive investigation of flexibility, operability, and the life concerns of this type of gas turbines.

Adiabatic behavior of gas wells due to natural reservoir fines migration: analytical model and CFD study

The adiabatic behavior of natural gas production well is frequently neglected in the reservoir formation damage study. The temperature of surrounding formation contributes to the smooth flow of natural gas in the wellbore. The heat transfer from the formation and geothermal gradient plays vital role in the efficient transport of gas in the subsurface formation and wellbore. But, fine particles which are attached to the rock surface migrate and are trapped in the pore throats, and as a result, there is deterioration in the permeability. The detachment of fines occurs due to high reservoir temperature and gas internal energy and temperature. Therefore, this paper conducts theoretical and numerical investigations on the adiabatic behavior of natural gas production well due to in situ reservoir fines migration. Firstly, an analytical model is developed and then, numerical models were constructed using CFD simulation tool to study the adiabatic nature of a gas well. A total of 24 cases were run in simulation, and input temperatures such as 200 °C, 250 °C, 300 °C, 350 °C, 400 °C and 450 °C were given for modeling. The results revealed that there was no sign of heat transfer from the wellbore to the surroundings. There was a heat circulation only within the wellbore. During the adiabatic state, the pressure in the central zone of the gas well is moderate, but rises linearly on the radial sides.

Development and validation of a hybrid temporal LES model in the perspective of applications to internal combustion engines

CFD simulation tools are increasingly used nowadays to design more fuel-efficient and clean Internal Combustion Engines (ICE). Within this framework, there is a need to benefit from a turbulence model which offers the best compromise between prediction capabilities and computational cost. The Hybrid Temporal LES (HTLES) approach is here retained within the perspective of an application to ICE configurations. HTLES is a hybrid Reynolds-Averaged Navier Stokes/Large Eddy Simulation (RANS/LES) model based on a solid theoretical framework using temporal filtering. The concept is to model the near-wall region in RANS and to solve the turbulent structures in the core region if the temporal and spatial resolutions are fine enough. In this study, a dedicated sub-model called Elliptic Shielding (ES) is added to HTLES in order to ensure RANS in the near-wall region, regardless of the mesh resolution. A modification of the computation of the total kinetic energy and the dissipation rate was introduced as first adaptions of HTLES towards non-stationary ICE configurations. HTLES is a recent approach, which has not been validated in a wide range of applications. The present study intends to further validate HTLES implemented in CONVERGE code by examining three stationary test cases. The first validation consists of the periodic hill case, which is a standard benchmark case to assess hybrid turbulence models. Then, in order to come closer to real ICE simulations, i.e., with larger Reynolds numbers and coarser near-wall resolutions, the method is validated in the case of a channel flow using wall functions and in the steady flow rig case consisting in an open valve at a fixed lift. HTLES results are compared to RANS k-ω SST and wall-modeled LES σ simulations performed with the same grid and the same temporal resolution. Unlike RANS, satisfactory reproduction of the flow recirculation has been observed with HTLES in the case of periodic hills. The channel flow configuration has underlined the capability of HTLES to predict the wall friction properly. The steady flow rig shows that HTLES combines advantages of RANS and LES in one simulation. On the one hand, HTLES yields mean and rms velocities as accurate as LES since the scale-resolving simulation is triggered in the core region. On the other hand, hybrid RANS/LES at the wall provides accurate pressure drop in contrast with LES performed on the same mesh. Future work will be dedicated to the extension of HTLES to non-stationary flows with moving walls in order to be able to tackle realistic ICE flow configurations.

CFD SIMULATION OF A CENTRIFUGAL PUMP IMPELLER WITH VARIATIONS OF NUMBER OF BLADES

The purpose of this paper is to model and simulate the water flow into the impeller of a centrifugal pump. Using CFD techniques two impellers were modeled, differing only by the number of blades of each one (6 and 10). From the results of the simulations, the impeller’s characteristic and the results were compared for each impeller. The model with 10 blades was more efficient for a real application of a centrifugal pump. All the results have shown themselves consistent with the turbomachinery theory, proving the efficiency of CFD simulation tools in the project of this kind of equipment

Steady-State Calibration of a Diesel Engine in Computational Fluid Dynamics Using a Graphical Processing Unit-Based Chemistry Solver

The prospect of analysis-driven precalibration of a modern diesel engine is extremely valuable in order to significantly reduce hardware investments and accelerate engine designs compliant with stricter fuel economy regulations. Advanced modeling tools, such as CFD, are often used with the goal of streamlining significant portions of the calibration process. The success of the methodology largely relies on the accuracy of analytical predictions, especially engine-out emissions. However, the effectiveness of CFD simulation tools for in-cylinder engine combustion is often compromised by the complexity, accuracy, and computational overhead of detailed chemical kinetics necessary for combustion calculations. The standard approach has been to use skeletal kinetic mechanisms (∼50 species), which consume acceptable computational time but with degraded accuracy. In this work, a comprehensive demonstration and validation of the analytical precalibration process is presented for a passenger car diesel engine using CFD simulations and a graphical processing unit (GPU)-based chemical kinetics solver (Zero-RK, developed at Lawrence Livermore National Laboratory, Livermore, CA) on high performance computing resources to enable the use of detailed kinetic mechanisms. Diesel engine combustion computations have been conducted over 600 operating points spanning in-vehicle speed-load map, using massively parallel ensemble simulation sets on the Titan supercomputer located at the Oak Ridge Leadership Computing Facility. The results with different mesh resolutions have been analyzed to compare differences in combustion and emissions (NOx, carbon monoxide CO, unburned hydrocarbons (UHC), and smoke) with actual engine measurements. The results show improved agreement in combustion and NOx predictions with a large n-heptane mechanism consisting of 144 species and 900 reactions with refined mesh resolution; however, agreement in CO, UHC, and smoke remains a challenge.

CFD Analysis of Hot Air Recirculation in Cooling System of Off Road Vehicle

The demands on cooling system of an off-road vehicle have increased due to charge air cooling, air conditioning and higher horsepower (hp) engines. In order to maximize cooling system performance of an off-road vehicle, the temperature of air entering the cooling system through front grill should be as low as possible, ideally at ambient temperature. Hot air exiting the cooling system which finds its way back to the front grill decreases the system performance. This is called as hot air recirculation. To study hot air recirculation complete vehicle is placed in physical wind tunnel facility. With CFD simulation tool this hot air recirculation can be studied in a virtual wind tunnel. Current paper studies hot air recirculation & quantifies the recirculation using CFD tool. Influence of tail wind velocity on recirculation was studied. The results of simulations were compared with experimental results.

Finite Element Analysis of Composite Ceramic-Concrete Slab Constructions Exposed to Fire

In this research, conjugated thermal and fluid dynamics simulations are presented on a modern hollow clay slab blocks filled pre-stressed reinforced concrete beam slab construction. The simulation parameters were set from Eurocode standards and calibrated using data from standardized fire tests of the same slab construction. We evaluated the temperature distributions of the slabs under transient conditions against standard fire load. Knowing the temperature distribution against time at certain points of the structure, the loss of load bearing capacity of the structure is definable at elevated temperatures. The results demonstrated that we could pre-establish the thermal behavior of complex composite structures exposed to fire using thermal and CFD simulation tools. Our results and method of fire resistance tests can contribute to fire safety planning of buildings.