Advanced Computational Fluid Dynamics Research Articles

Mass Transport-Enhanced Electrochemical Processes Using Newly Developed Axial Flow Electrochemical Reactor

Electrochemical processing is attracting renewed interest in industry, particularly for the partial or complete synthesis of chemicals and the removal of a range of contaminants and pathogens from water. This renewed interest is driven by the cleanliness of electrochemistry; direct reduction or oxidation of target species at an electrode avoids the use of potentially harmful auxiliary chemicals, which is an increasingly important benefit that offsets the electrical energy that is required.Although electrochemical processing is used widely, there is still scope to improve its efficiency in many industrial applications. In this respect, a particularly common problem is mass transport. At the atomic level, electrons are transferred between an electrode and a reactant by tunneling - a process whose probability diminishes exponentially with distance - so the reactant species must reside within just a few atomic layers of the surface for electron transfer is to take place at a reasonable rate. However, this means the solution must be mixed at all practical scales of length if mass transport is to be efficient, a result that is particularly difficult to achieve. Although mixing is well-studied both practically and theoretically, it is still an imperfect science. In a relatively recent advance, the term chaotic advection was introduced to describe the exponential dividing of fluid filaments during flow that produces particularly efficient mixing. Two significant points about chaotic advection are: it commonly includes both laminar and turbulent flow regimes, andstatic mixers can be efficient devices for generating chaotic advection. An axial flow electrochemical cell is conceptually simple but practical examples are infrequently encountered in both industry and research. Achieving efficient mixing throughout the length of the cell is perhaps the greatest obstacle to the adoption of this otherwise efficient geometry. The CSIRO flow electrochemical cell aims to address these issues by using advanced computational fluid dynamics (CFD) to design, manufacture and optimize an electrode that can maximize mixing within an axial flow cell. The current design of the CSIRO electrochemical flow cell employs an additively manufactured, high surface area static mixer as a central working electrode that fits snugly within a tubular porous polymeric separator which defines a working compartment. In addition, an inert tubular counter electrode surrounds the working compartment at a small distance from the separator, creating a low volume counter compartment and formed the outside casing of the cell (Figure 1).In this work, the CSIRO flow electrochemical cell has been characterized using the reduction of ferricyanide, [Fe(CN)6]3+) at three different reactant concentrations and seven different flow rates. Results show that the cell can accelerate the rate of the reduction reaction compared to other classical electrochemical systems. Thus, the suitability of the flow cell was studied for water treatment (purification/disinfection) applications. Extensive physical, chemical and electrochemical characterization techniques were used in this investigation to evaluate the cells performance. Figure 1

Contactless pick-and-place of millimetric objects using inverted near-field acoustic levitation

We model and realize an ultrasonic contactless pick-and-place device capable of picking, self-centering, self-orienting, translating, and releasing flat millimetric objects. The device is an ultrasonic Langevin transducer operating at 21 kHz that radiates into air through a tapered tip. Objects are trapped few micrometers below the tip due to the near-field acoustic levitation phenomenon. We first investigate the conditions to achieve an attractive force on the object depending on its size and the device operating frequency. Second, we use a 3D acoustic model that describes the converging forces and torque that provide the self-centering and self-orienting capabilities. Third, a more advanced Computational Fluid Dynamics model based on the Navier–Stokes equations explains the small gap between the tip and the trapped object. The contactless manipulation capabilities of the device are demonstrated by picking, transporting, and releasing a Surface Mount Device in air. The presented manipulation concept can be an interesting alternative for manipulating delicate objects such as microelectromechanical devices, silicon dies, or micro-optical devices.

A Critical Review on the Application of Computational Fluid Dynamics in Centrifugal Turbomachines

Centrifugal turbomachines are the popular type of power absorbing machines especially used in many industrial applications. In these devices the energy from the rotating impeller is transferred to the fluid to increase its pressure energy. The flow phenomena in these machines is very complex because of the presence of adverse pressure gradients in the flow passages. The level of complexity of turbomachinery flow fields is directly influenced by flow-path geometry and component blade geometry. Hence there is a dire need of advanced flow modelling techniques to understand and capture the fluid characteristics in these flow devices. To design such flow domains, advanced Computational Fluid Dynamics (CFD) tools are required that are capable of accurately modelling the complex flows encountered in turbomachinery applications. These models reflect the full three-dimensional, turbulent, transonic, and often unsteady nature of the actual flows. In addition, they must allow analyses to be performed in reasonable amounts of time that can be accommodated within a typical design cycle. With the development of fast and validated numerical methods, and the continuous improvement in clock speed of computer processors, highly complex problems are now being solved using CFD methods even more economically and quickly. This article focusses the efficacy of CFD tools in turbomachinery applications and various parametric methodologies pertaining to efficiency improvement of turbomachines in detail.

Operational fatigue loading on tidal turbine blades using computational fluid dynamics

As the world moves to a greater reliance on renewable energy, a vital component will be the predictability and dependability of the energy source; tidal energy provides such a solution. Horizontal axis tidal turbines are the most mature technology of all the marine renewable energy devices currently under development, as full-scale porotypes are already being tested and operated. As the industry develops and strives for commercial viability, it is becoming increasingly vital to develop a robust understanding of the complex interaction between the tidal flow, turbine blades and the support structure. This study uses an advanced computational fluid dynamics model to explore the operational fatigue loadings induced on tidal turbine blades. Two factors are considered, the presence of a support structure and varying vertical velocity profile of the tidal current. In order to perform the investigation, a model of a concept 16 m diameter horizontal axis tidal turbine with a monopile support structure is created. An investigation of the operational fatigue loadings due to variations in the positioning and the diameter of the support structure, the tidal turbine blade loads were found to varying by up to 43% of the maximum total thrust force.

Heat Transfer Prediction for Methane in Regenerative Cooling Channels with Neural Networks

Methane is considered a good choice as a propellant for future reusable launch systems. However, the heat transfer prediction for supercritical methane flowing in the cooling channels of a regeneratively cooled combustion chamber is challenging. Because accurate heat transfer predictions are essential to design reliable and efficient cooling systems, heat transfer modeling is a fundamental issue to address. Advanced computational fluid dynamics (CFD) calculations achieve sufficient accuracy, but the associated computational cost prevents an efficient integration in optimization loops. Surrogate models based on artificial neural networks (ANNs) offer a great speed advantage. It is shown that an ANN, trained on data extracted from samples of CFD simulations, is able to predict the maximum wall temperature along straight rocket engine cooling channels using methane with convincing precision. The combination of the ANN model with simple relations for pressure drop and enthalpy rise results in a complete reduced-order model, which can be used for numerically efficient design space exploration and optimization.

Multi-jet gas cooling of in-beam foils or specimens: CFD predictions of the convective heat-transfer coefficient

An experiment was designed to investigate the possible enhancement of the convective heat-transfer coefficient by utilizing multiple, parallel jets in the cooling of a small heated surface, such as typically induced by an accelerated ion beam on a thin foil or specimen. The hot spot was provided using a small electrically heated plate. It was found that heat-transfer calculations by means of simple empirical methods based on dimensional analysis are not useful in this case and that advanced computational fluid dynamics (CFD) mod-elling is essential to interpret the results. It is shown that enhanced convective cooling can indeed be obtained with a multi-jet configuration as compared to a single-jet configuration but only under very selective conditions. An improperly designed multi-jet configuration can also provide significantly reduced cooling relative to the single-jet case and the estimation of the behavior of any particular jet geometry is eminently non-intuitive. CFD provides acceptable quantitative results and seem to be the only tool available to gain an understanding of these complex flows where simple models and “rules of thumb” cannot be relied upon. – LA-UR-18-29455

Experimental Validation of a Numerical Model of a Ventilated Façade with Horizontal and Vertical Open Joints

Commercial and residential building is one of the four major final energy consumption and end-use sectors. In this sector, cooling loads represent an important part of the energy consumption, and therefore, they must be minimized, improving the energy efficiency of buildings. Ventilated façades are one of the most widely used passive elements that are integrated into buildings, precisely with the aim of reducing these loads. This reduction is due to the airflow induced in the air cavity by the buoyancy forces, when the solar radiation heats the outer layer of the façade. In the open joint ventilated facades (OJVF), ventilation is attained through the open joints between the panels composing the outer layer. Despite the steadily growing research in the characterization of this type of system, few studies combine the numerical modelling of OJVF with experimental results for the assessment of the airflow in the ventilated cavities. This paper experimentally validates a numerical simulation model of an OJVF. Firstly, the façade performance has been experimentally assessed in a laboratory model determining the temperatures in the panels and air gap and measuring the flow field at the gap using particle image velocimetry (PIV) techniques. Secondly, a numerical model has been developed using advanced Computational Fluid Dynamics (CFD) simulation tools. Finally, an experimental validation of the numerical model has been done. Experimental and numerical results are compared in different planes inside the ventilated cavity. The discrete ordinates (DO) radiation model and the k-ε renormalisation group (RNG) turbulence model better adjust the simulated results to the experimental ones.

CFD code-to-code benchmarking on simulation of fire and smoke propagation for nuclear applications

Abstract The nuclear industry has seen an increased use of Computational Fluid Dynamics (CFD) technology as a high-fidelity tool for design-basis and beyond design-basis accident simulations. For fire hazards, detailed experimental investigation in a realistic environment is often impractical. Therefore, the use of an advanced 3D CFD modeling approach to predict smoke and fire propagation has risen, especially for nuclear power plant fire modeling applications. CFD simulations can include major contributing and mitigating mechanisms regarding the fire propagation and its consequences, in fine detail and under realistic geometry conditions. In addition, accurate simulations of unsteady 3D fire and smoke spread, in conjunction with evacuation analyses, can be used to establish effective emergency evacuation strategies. In the present study, the fire and smoke propagation in a main control room was modelled using Reynolds-Averaged Navier-Stokes Equation based twoequation turbulence models and a Large Eddy Simulation model implemented in a commercial CFD code, Siemens STAR-CCM+. The predictions from STAR-CCM+ were compared with those obtained in a previous study using the NIST Fire Dynamic Simulator (FDS) code. Although higher temperature was predicted at the fire source by STAR-CCM+, the current study predicted trends similar to the FDS results with some minor differences at the operator location. A follow-up study is currently underway to investigate the factors affecting the differences, including further assessment of codes against available benchmark experiments.

Validation of the Steady-State Hover Formulation for Accurate Performance Predictions

This paper shows accurate predictions for hover performance regardless of planform geometry, blade-tip Mach number, or disk loading. To prove this statement, sensitivity analyses were performed along with performance predictions for four rotor designs. Planform effects were also studied, such as the blade anhedral, showing the strong sensitivity of the rotor blade performance due to geometric features. The steady-state solution methodology with imposed Froude boundary conditions is shown to give accurate results for relatively coarse grid sizes. This approach leads to reduced computational costs as compared to time-dependent simulations. It is also recognized that, given the current accuracy of the available experimental data, the use of more advanced computational fluid dynamics methods may not be fully justified. To advance the accuracy of modern computational fluid dynamics methods, a comprehensive experimental dataset is required.

High-fidelity velocity measurements in a totally blocked interior subchannel of a wire-wrapped 61-pin hexagonal fuel bundle

Liquid metal fast reactors typically utilize a tightly packed triangular lattice of fuel pins helically wrapped with a wire spacer and enclosed in a hexagonal duct. During reactor operation partial or total flow blockage of coolant channels may occur at different locations of the fuel assembly. Due to potential isolated or combined causes, these blockages may include collection and accumulation of debris, and cladding deformation. The complexity of the flow behavior and heat transfer phenomena within a wire-wrapped fuel assembly accompanied with the effects of channel blockage has motivated the research community around the world, initiating extensive experimental and numerical investigations. The 61-pin wire-wrapped experimental bundle at Texas A& M University, with its clear, fully accessible test section, has been designed, constructed, and operated to conduct high-resolution measurements of the flow characteristics at different locations within the bundle. High spatial and temporal resolution measurements of the velocity fields within vertical and horizontal planes at different locations in test bundle have been produced using advanced laser-based techniques. The pressure at different axial and azimuthal locations in the bundle has been measured within a wide Reynolds number range to investigate laminar, transitional, and turbulent flow regimes. In this article new high-resolution measurements of the velocity fields and turbulent characteristics within a totally blocked interior subchannel are presented. The time-resolved particle image velocimetry (TR-PIV) measurements have been performed within the interior subchannel of the wire wrapped fuel bundle, under the presence of a localized, total blockage of one of the subchannels near the center pin. From the obtained velocity fields the first and second-order flow statistics, such as mean velocity, root-mean-square fluctuating velocity, and Reynolds stress, are computed and presented. Spectral analysis was performed to the fluctuating velocity and the vortex shedding frequency was found at St=0.16. Finally, proper orthogonal decomposition (POD) analysis was applied to the instantaneous velocity fields to extract the coherent flow structures in the flow region downstream of the blockage. The experimental results produced not only provide a better understanding of the flow behaviors under a channel blockage, but also support the validation of commercial and advanced Computational Fluid Dynamics (CFD) codes with a unique set of experimental data.

Online in situ prediction of 3-D flame evolution from its history 2-D projections via deep learning

Online in situ prediction of 3-D flame evolution has been long desired and is considered to be the Holy Grail for the combustion community. Recent advances in computational power have facilitated the development of computational fluid dynamics (CFD), which can be used to predict flame behaviours. However, the most advanced CFD techniques are still incapable of realizing online in situ prediction of practical flames due to the enormous computational costs involved. In this work, we aim to combine the state-of-the-art experimental technique (that is, time-resolved volumetric tomography) with deep learning algorithms for rapid prediction of 3-D flame evolution. Proof-of-concept experiments conducted suggest that the evolution of both a laminar diffusion flame and a typical non-premixed turbulent swirl-stabilized flame can be predicted faithfully in a time scale on the order of milliseconds, which can be further reduced by simply using a few more GPUs. We believe this is the first time that online in situ prediction of 3-D flame evolution has become feasible, and we expect this method to be extremely useful, as for most application scenarios the online in situ prediction of even the large-scale flame features are already useful for an effective flame control.

CFD analysis of the erosion of a light gas stratification by means of a hot air jet in the MiniPanda facility

Following the Fukushima-Daiichi accident, many countries decided to strengthen the safety systems of their nuclear power plants in order to increase the capabilities of managing severe nuclear accidents. To achieve this goal detailed analysis of postulated design and beyond-design-basis accidents is essential. The main tools available for the analysis of these complex scenarios are Advanced Lumped Parameters (LP) and Computational Fluid Dynamics (CFD) codes. Currently, the most limiting factor in the application of these tools is their validation. This activity is performed in support of the development and validation of a CFD model, built in the numerical environment of OpenFOAM, for hydrogen behavior in the containment of Light Water Reactors. For validation purpose, numerical simulations of the erosion of a light gas stratification by means of a hot air jet have been performed, and results of the simulations were analysed and compared against experimental results obtained by Ritterath (2012) in the MiniPanda facility. Two different scenarios have been considered, each characterized by a different value of the mass flow rate of the jet used to erode the stratification.

Feed temperature effect on separation performance of industrial hydrocyclone: advanced CFD analysis

ABSTRACT Because of weather or operating conditions, the feed temperature variation is considered as an important parameter that could eventually affect the separation performances of hydrocyclones. It is proposed in this work to analyze numerically the influence of this operating parameter on industrial hydrocyclone performance. A novel correlation derived by Computational Fluid Dynamics (CFD) was proposed to estimate the Euler number of hydrocyclones that are geometrically similar to that studied in the present work. Two other relationships are also proposed to calculate the Euler number and the cut-off diameter from already known values measured under the same operating conditions but at a different temperature.

One-dimensional modeling of fractional flow reserve in coronary artery disease: Uncertainty quantification and Bayesian optimization

Non-invasive estimation of fractional flow reserve (FFR) values, the key index in the diagnosis of obstructive coronary artery disease, is a promising alternative to traditional way of performing invasive coronary angiography. With the advances in computational fluid dynamics (CFD), one can estimate FFR based on the solution obtained in a reconstructed coronary geometry from coronary computed tomography (CT) angiography. However, the computational cost to perform three-dimensional (3D) simulations has limited the use of CFD in most clinical settings. This could become more restrictive if one aims to quantify the uncertainty associated with FFR calculations due to the uncertainty in anatomic and physiologic properties as a significant number of 3D simulations is required to sample a relatively large parametric space. We have developed a predictive probabilistic model of FFR, which quantifies the uncertainty of the predicted values with significantly lower computational costs. Based on global sensitivity analysis, we first identify the important physiologic and anatomic parameters that impact the predictions of FFR. Our approach is to employ one-dimensional blood flow simulations of coronary trees that offer fast FFR predictions with uncertainty quantification in computing blood pressure and flow distributions within the coronaries. This is complemented with a multifidelity algorithm that is used to infer their optimal values using available patient-specific clinical measurements.

A Novel Flow Electrochemical Reactor for Intensifying Diffusion-Limited Electrochemical Processes

Electrochemical processing is attracting renewed interest in industry for synthesis of chemicals or for the removal of a range of contaminants because it is cleaner than most alternatives. Redox reactions that are controlled by applying a potential between two electrodes avoid the use of potentially harmful auxiliary chemicals, an increasingly important advantage that offsets the electrical energy that is required. However, electrochemical processing is still limited in many applications by electrochemical engineering issues such as electrode material selection and construction, efficiency losses caused by mass transfer limitations and batch mode of operation. The CSIRO flow electrochemical cell aims to address these issues by using advanced computational fluid dynamics (CFD) to design, manufacture and optimize an electrode that can maximize mixing within an axial flow cell. The static mixer working electrode is made using additive manufacturing techniques that allows complex designs to be realised using a range of different metals with different surface roughnesses. The current design of the CSIRO electrochemical flow cell employs an additively manufactured, high surface area static mixer as a central working electrode that fits snugly within a tubular porous polymeric separator which defines a working compartment. Two ports at either end of the electrode, manufactured as an integral part of the design provide connections for fluid flow. As with all static mixers, the momentum of the solution induces mixing as it flows past the electrode surface. In the current version of the cell, an inert tubular counter electrode surrounds the working compartment at a small distance from the separator, creating a low volume counter compartment and formed the outside casing of the cell. Separate ports provide fluid flow into this latter compartment. Figure 1 shows a schematic drawing of one configuration of the electrochemical cell with the arrangement of the electrodes, the fluidic setup including the peristaltic pump(s) used to control the solution flow into and out of the cell and the power supply connection to the cell. The efficiency with which the cell works may be evaluated by comparing the limiting current measured at various flow rates with results from a Rotating disk electrode (RDE) in the same solution. These comparisons are useful indicators of performance only, and are not used to draw any conclusions about the hydrodynamic conditions at the static mixer surface. The CSIRO flow electrochemical cell has been characterized using the reduction of Ferricyanide, [Fe(CN)6]3+) at three different reactant concentrations and seven different flow rates. Results show that the cell can accelerate the rate of the reduction reaction by nearly forty-five times. As expected, the rate of this acceleration is highest when the reaction is diffusion limited, so the impact is seen most clearly in dilute solutions. By comparison, results obtained with an RDE were not as promising confirming the effectiveness of the CSIRO designed flow electrochemical cell. Exhaustive electrolysis experiments were also undertaken to show how effectively the cell can remove contaminants from a fixed volume of a contaminated aqueous solution. A two Litre solution of copper contaminated water (i.e. 100 pm CuSO4.4H2O in 0.01M H2SO4) was processed using the flow cell at a constant flow rate of 100 mL/min for 5 hours. SEM/EDS results confirmed the deposition of copper ions onto the static mixer working electrode. ICP results showed that a 50% reduction in the copper concentration from 100 ppm to 51 ppm was achieved in 5 hours which is encouraging. Figure 1

Vibro-acoustics response of a simplified glass window excited by the turbulent wake of a quarter-spherocylinder body.

Inside vehicle cabins, an important part of interior noise is generated from cabin window vibration. The vibration is stimulated by surface pressure fluctuations that are produced by exterior flows and flow-induced noise. To numerically investigate the cabin noise, both exterior flows and noise must be resolved in simulations. This requirement motivates us to utilize advanced computational fluid dynamics (CFD) and computational aeroacoustics (CAA) based on a quarter-spherocylinder body, which is a general model for vehicle mirrors. The blunt body is mounted upstream of a rectangular window of a cuboid cavity. The turbulent flow is simulated using compressible large eddy simulation, compressible detached eddy simulation, and incompressible detached eddy simulation (I-DES). The exterior noise is either predicted by coupling the I-DES with an acoustic wave modeling method, or directly solved using compressible CFD methods. Given surface pressure fluctuations on the window from the CFD and CAA methods, the window vibration and interior noise are simulated with a finite element method. The effects of compressibility, turbulence modeling methods, and grid topology (polyhedral and trimmed elements) are discussed. The computational efficiency of the numerical methods is addressed. The contributions of hydrodynamic and acoustic pressure fluctuations to the interior noise are clarified.

3D computational fluid dynamics simulation of a 3-fluid liquid-to-air membrane energy exchanger (LAMEE)

In this article, a 3-fluid liquid-to-air membrane energy exchanger (LAMEE) prototype has been modeled using 3D computational fluid dynamics (CFD) technique. Applying advanced CFD simulation along with UDF (User Defined Function) and UDS (User Defined Scalar) external computer programs are major efforts of the present study which have overcome some computational restrictions of conventional numerical simulation software. Therefore, additional equations of mass and energy transfer are accompanied with fundamental governing equations of Newtonian fluid flow to explore the complexity of numerical analysis. The rates of conjugate heat and moisture transfer through the membrane, air and desiccant exit temperatures and the cooling effect of the refrigeration tubes are evaluated and shown in detail. The calculated temperature and humidity ratio at the outlet of the 3-fluid LAMEE agree well with available experimental data. The present CFD simulation reveals the diverse cooling effect of the different refrigeration tubes in the 3-fluid LAME depending on their individual geometrical location. The refrigeration tubes increase the sensible, latent and total effectiveness, moisture removal rate and sensible cooling capacity 72%, 29%, 41%, 13.0 gv/h and 8.7 W, respectively. The obtained temperature and humidity ratio contours and flow patterns throughout the 3-fluid LAMEE reveal the mechanisms of dehumidification, cooling and phase change.

A flight demonstration for airframe noise reduction technology

This article overviews activities and results for an initial flight demonstration of a project, FQUROH, to develop and mature airframe noise reduction technologies. The project aims to demonstrate technologies for reducing airframe noise through three flight tests using aircraft with modified high-lift devices and landing gear. It intends to verify the design methods that utilize advanced computational fluid dynamics (CFD) and the feasibility of practical noise reduction concepts. The main purposes of the initial demonstration using a JAXA’s research aircraft in 2016 were to establish the processes for flight testing, including modification of the aircraft and experimental procedures, as well as to evaluate preliminary noise reduction designs. In the design process, noise reduction concepts for the flap and main landing gear were successfully applied to the actual complex geometries of the aircraft using advanced CFD, and the noise reduction effects were confirmed with noise measurements in wind tunnel tests. Based on the designs, the flap and main landing gear modifications were manufactured and installed on the aircraft. The flight demonstration campaign was successfully carried out with 177 noise source measurements, and encouraging results were obtained that show the feasibility of the noise reduction design method.

Aerodynamic Tailoring of Structures Using Computational Fluid Dynamics

ABSTRACT Tall buildings and long span bridges exposed to wind undergo complex interactions, which precludes a functional relationship between wind and its load effects. In digital age with burgeoning growth in computational resources and parallel advances in computational fluid dynamics, computational simulations are evolving with a promise of becoming versatile, convenient and reliable means of assessing wind load effects. This paper provides an overview of the current state-of-the-art on the CFD based simulations of wind loads on structures by delineating the differences in the modeling of streamline nature of airfoils versus complex profiles of civil structures. This is followed by highlighting the merits and shortcomings of three modeling schemes central to CFD, i.e. RANS, LES and DNS. Topics related to generation of inflow conditions and fluid-structure interactions are discussed. A case study involving aerodynamic shape sculpting of tall buildings that requires examining several configurations is presented. While such an assessment is currently performed via wind tunnels with limited set of configurations, CFD promises to discover the optimal configuration in a large search space. In closing, future prospects, e.g. advances in multi-fidelity models and the role and propagation of input and modeling uncertainties in CFD simulation are presented.

Numerical and experimental analysis of the air stream generated by square ceiling diffusers

Ceiling diffusers are one of the most important elements of ventilation and air-conditioning installations. They have a significant impact on the speed and temperature distribution of air. The basic task of these devices is to provide the required air stream while maintaining its appropriate parameters in the occupied zone and low noise levels in the room. Square ceiling diffusers are designed for use in low- and medium-pressure ventilation systems. The diffusers allow obtaining 1, 2, 3 or 4-way air supply. Knowledge of the airflow formed by the diffuser is essential in order to ensure the comfort of people staying in a ventilated room. Designers of the diffusers nowadays mainly use advanced software and CFD (Computational Fluid Dynamics) modelling technique. CFD methods allow to quickly analyse the fluid flow. However, an very important problem is the consistency of the results obtained by numerical methods with the results obtained on an experimental way. The work presents a laboratory stand designed to test ceiling diffusers. In this research study the single square ceiling diffuser was experimentally and numerically analysed.