CFD Simulation Research Articles (Page 1)

Abstract In the current state of technology, gas turbines operate mainly with fossil fuels. In order to achieve a sustainable energy supply with gas turbines alternative fuels have to be used. In the past, many attempts have been made to use alternative fuels, such as solid biogenic fuels. The main problem with the use of these fuels has been the fouling of the turbine stages during operation. To counteract this problem, the use of film cooling as a protective mechanism to reduce deposits is considered in this work. In the past, studies have already shown that this application can reduce particle deposits. For this purpose, test blades with film cooling were created and exposed to an increased particle load in a test rig. Synthetically produced ash, which corresponds to the typical components of biogenic utilization, was used as test ash for the deposition tests. The deposits were analysed by means of a visual inspection paired with a REM-EDX examination. The deposition tests were additionally supported by CFD simulations and compared with the particle Stokes number. Overall, film cooling appears to be a suitable means of reducing deposits on a turbine blade. However, the geometric design needs to be modified compared to the classical film cooling setup. In addition, low momentum flux ratios and a delay of the flow seem to be favourable for film cooling as a protective mechanism. The blade deflection angle also plays an important role in the implementation of the new design.

Solar thermal energy plays a vital role among renewable energy sources, with enhancing solar collector performance remaining a key research priority. This study investigates the efficiency improvement of a mini-channel flat plate collector integrated with a novel composite phase change material (CPCM), Pb(NO3)2 -NaNO3 -NaCl/Boron Nitride. The incorporation of CPCM effectively minimizes heat loss, stores surplus thermal energy, and provides passive cooling to the collector. Experimental results revealed that the collector outlet temperature decreased from 62°C to 52°C, resulting in a thermal efficiency of 90%. The maximum power output reached 400 W, while the system stored 50 kJ of thermal energy. The CPCM exhibited a melting temperature of 110°C and a solidification temperature of 115°C, maintaining stability with only a 2°C variation after multiple thermal cycles. Thermogravimetric analysis confirmed excellent stability with 40% degradation at 700°C. Furthermore, the CPCM demonstrated a thermal conductivity of 0.92 W/m ċ K, a latent heat of 12.53 J/g, and a specific heat capacity of 0.64 J/g ċ K. The mini-channel configuration enhanced heat flux by 30% with a pressure drop of 100 Pa at 6 L/min flow rate. CFD simulations conducted using Python verified that CPCM integration and the mini-channel design substantially improved collector performance.

Abstract We introduce an inexpensive experimental setup for analyzing free-surface water waves: a 1 m long tabletop flume made from perspex, driven by a variable-frequency piston wavemaker built from Lego. Using mobile-phone video capture, we collect experimental data and compare it with predictions from linear gravity-capillary wave theory and with multiphase simulations performed in OpenFOAM. We find excellent quantitative agreement across all three approaches. Our setup may be valuable for students with a background in Mathematical Modelling who lack hands-on laboratory experience. To explore this, we report on a survey of students who completed an integrated theoretical, experimental, and computational project. While students found the experience enhanced their learning of Fluid Mechanics, they also noted the need for better support in setting up and running CFD simulations.

Purpose The purpose of this paper is to construct a human body-garment-environment integrated model in CFD simulation to evaluate the heat flow change in an outdoor service shirt. The proposed model as well as the method can be used to analyze the undergarment microenvironment and to predict the thermal comfort of the garment. Design/methodology/approach In this paper, the clothing fabric in the climate chamber was considered as a classical porous medium model, and the heat transfer mechanism in the microenvironment of a thermal manikin wearing a single-layer long-sleeved outdoor service shirt was investigated by using the thermostatic method under different levels of wind environments. The human body model consistent with the thermal manikin and the relevant clothing model of a shirt with the real size is established by using CLO3D software. Heat transfer and fluid change in a single-layer shirt subjected to the wind were simulated in an FEM software. The mathematical model of heat transfer and fluid changes in a single-layer shirt subjected to wind was established. Findings By using the physical property parameters of the real fabric materials, experiments were conducted with different wind speeds, combined with the simulation function of the climate chamber using the thermostatic method. Finally, numerical simulation results were analyzed and compared to the results of a real thermal manikin to validate the feasibility of the simulation of the characteristics of the change of heat flow under the clothing of the single-layer outdoor service shirts in FLUENT. The relative error between the simulation results and the actual results of the space temperature in each region under the garment using this numerical simulation technique was explored, with an error range of <6.67%, verifying the feasibility of the simulation model. Originality/value A human body-garment-environment integrated model in CFD simulation was established to evaluate the heat flow change in a typical shirt. The detailed parameters of the shirt fabric were determined by testing all aspects of the garment fabric. The actual porosity of the sample outdoor service shirt was determined by mercuric pressure, and the parameters obtained were used to create a closer simulation of the material data. A real-size human body model and the relevant garment model were created in the simulation process. The method provided a feasible numerical way to evaluate and predict heat transfer and the microenvironment of the garment and to produce robust and reliable simulation performance.

Wind turbine blades, as a fundamental component of the wind power generation system, will interact with the flow field throughout operation. This interaction will substantially influence their aerodynamic performance and structural response. This paper establishes a computational fluid dynamics and dynamic finite element analysis (CFD-DFEA) model to address the issue of inaccurate simulation results due to model simplification in prior fluid-structure interaction (FSI) research. This model comprehensively accounts for the actual ply structure of the blade. Simultaneously, to mitigate the high computational expense of two-way FSI simulations for wind turbine blades, an innovative equivalent approach is proposed for determining blade surface pressure while integrating two-way FSI effects. This method introduces a coupling coefficient λ to adjust the blade pressure coefficient C p derived from basic CFD simulations, is adjusted to effectively represent the blade surface pressure distribution while accounting for the FSI effect, enabling accurate calculation of the blade surface pressure. Comparing the power output and load of wind turbine blades under CFD simulation, two-way FSI simulation and empirical testing reveals that the model can precisely simulate the blade dynamics. It can accurately reflect the blade’s actual operation inside the flow field and precisely forecast aerodynamic loads. The proposed equivalent method can improve computation efficiency by 3.15 times while maintaining the simulation accuracy, providing a more cost-effective and efficient alternative for the load calculation of wind turbine blades.

ABSTRACT Severe dust accumulation issues in desert photovoltaic (PV) power stations are found to significantly reduce power generation efficiency. While existing studies have primarily focused on dust deposition characteristics of individual PV panels, systematic investigations into row spacing configurations of serially arranged arrays and their associated efficiency degradation models remain limited. Through integrated CFD simulations and accelerated deposition experiments, the effects of row spacing (20–50 cm), tilt angle (5°-45°), wind speed (1.3–3.9 m/s), and particle size (1–300 μm) on deposition patterns were systematically examined. A novel dust concentration-energy conversion efficiency (DC-ECE) model incorporating realistic particle size distributions was developed and successfully extended to practical engineering estimations. Key results indicate that the front panel’s deposition rate increases with tilt angle and peaks at about 6% for 45°, while the rear panel’s deposition is influenced by the attenuation of wake shielding, showing a 41.8% increase when spacing expands from 20 cm to 50 cm. A normally distributed deposition rate model, based on gas-solid flow simulations, reveals a nonlinear relationship between particle size and deposition. Efficiency degradation was quantified using a PV conversion model, providing theoretical guidance for optimizing array spacing, tilt angles, and cleaning schedules in desert PV plants. These findings offer practical solutions to mitigate power losses in arid regions.

The heart is the body’s core pump. Heart failure impairs the heart’s ability to pump blood, leading to circulatory disorders. The artificial heart (blood pump) is an important mechanical circulatory support device that can partially or completely substitute cardiac pumping function, potentially improving hemodynamic performance and alleviating symptoms of heart failure. A combination of computational fluid dynamics simulation and hydraulic performance testing was used to study key parameters of the impeller, including blade count, blade wrap angle, impeller flow path, and diversion cone height. The goal was to reduce hemolysis risk and enhance pumping efficiency. Increasing the blade count raised the head, with optimal efficiency achieved at seven blades. A larger blade wrap angle decreased the head but improved efficiency. Synchronizing the flow path and diversion cone height at 4.1 mm maximized the head. Under various rotational speeds, the studied hemolysis index remained well below 0.1 g/100 L. Both experimental and simulation data were validated against each other, meeting the required error tolerances. The studied blood pump meets the design specifications. At an operating condition of 5 L/min flow rate and 2800 rpm, the pump achieves the required head and hemolysis criteria with a margin of safety.

As large common areas, cruise ship atriums affect passenger comfort and HVAC efficiency. Due to their complexity and high occupancy, maintaining a suitable thermal environment is difficult. Experimental measurements, thermal load analysis, and CFD simulation are used to assess and improve the atrium’s summer thermal climate. Experimental data supported the use of the RNG k-ε turbulence model to forecast airflow and temperature. To meet the cooling demand of 28,784 W, a supply air volume of 10,742 m3/h was required. Various air-supply methods were evaluated for temperature distribution, airflow velocity, PMV, and air age. Larger diffusers and better air dispersion increased temperature homogeneity, air age, and comfort. Redistributing airflow to corridors reduced localized overheating but raised core temperatures, whereas adding diffusers without boosting supply volume caused interference. The configuration with larger diffuser areas and equilibrated airflow maintained a temperature of 21–23 °C, a PMV of −0.1 to 0.1, an air velocity of 0–0.3 m/s, and an average air age of 350 s. The findings provide theoretical and engineering guidance for energy-efficient HVAC systems in cruise ship atriums and other large public spaces.

Generation and diffusion characteristics of CO during excavation blasting in underground upward-inclination roadways: Based on field measurements and CFD simulations

Analysis of space nuclear reactor under accident conditions with CFD simulation and interpretable machine learning algorithm

Aerodynamic characteristics evaluation of a cable-stayed bridge - By CFD simulations

Investigating the aerodynamic characteristics of high-speed planing catamarans through wind tunnel tests, CFD simulations, and regression analysis

A semi-enclosed cavity receiver for linear fresnel reflectors: parametric analysis, CFD simulation and experimental study

Coupling an advanced actuator surface method with CFD for unsteady aerodynamic simulation of helicopter

CFD simulation of multifluid mixing and structure optimization of rotating liquid film reactor for magnesium hydroxide production

Carbon-free power generation strategy in South Korea: CFD simulation for optimization of ammonia injection and blending ratio in tangentially fired boiler

The CFD simulation of airflow characteristic and optimization design of dehumidification system of main cable in suspension bridge

Optimizing permeability of microporous scaffolds through CFD simulation to enhance osseointegration

CFD simulation of mass transfer in adsorption column: Numerical analysis of molecular diffusion and convection

With the acceleration of urbanization, environmental degradation is increasingly restricting the improvement of residents’ quality of life, and promoting the transformation of old communities has become a key path for sustainable urban development. However, existing buildings generally face challenges, such as the deterioration of the performance of the envelope structure and the rising energy consumption of the air conditioning system, which pose a serious test for the realization of green renovation. Inspired by the application of bionics in the field of architecture, this study innovatively designed five types of bionic envelope structures for outdoor air conditioning units, namely scales, honeycombs, spider webs, leaves, and bird nests, based on the aerodynamic characteristics of biological prototypes. The ventilation performance of these structures was evaluated at three scales—namely, single building, townhouse, and community—under natural ventilation conditions, using a CFD simulation system. The study shows the following: (1) the spider web structure has the best comprehensive performance among all types of enclosures, which can significantly improve the uniformity of the flow field and effectively eliminate the low-speed stagnation area on the windward side; (2) the structure reorganizes the flow structure of the near-wall area through the cutting and diversion of the porous grid, reduces the wake range, and weakens the negative pressure intensity, making the pressure distribution around the building more balanced; (3) in the height range of 1.5–27 m, the spider web structure performs particularly well at the townhouse and community scales, with an average wind speed increase of 1.1–1.4%; and (4) the design takes into account both the safety of the enclosure and the comfort of the pedestrian area, achieving a synergistic optimization of function and performance. This study provides new ideas for the micro-renewal of buildings, based on bionic principles, and has theoretical and practical value for improving the wind environment quality of old communities and promoting low-carbon urban development.