Throat Length Research Articles

Micro–Nano 3D CT Scanning to Assess the Impact of Microparameters of Volcanic Reservoirs on Gas Migration

Volcanic rock reservoirs for oil and gas are known worldwide for their considerable heterogeneity. Micropores and fractures play vital roles in the storage and transportation of natural gas. Samples from volcanic reservoirs in Songliao Basin, CS1 and W21, belonging to the Changling fault depression and the Wangfu fault depression, respectively, have similar lithology. This study employs micro–nano CT scanning technology to systematically identify the key parameters and transport capacities of natural gas within volcanic reservoirs. Using Avizo 2020.1software, a 3D digital representation of rock core was reconstructed to model pore distribution, connectivity, pore–throat networks, and fractures. These models are then analyzed to evaluate pore/throat structures and fractures alongside microscopic parameters. The relationship between micropore–throat structure parameters and permeability was investigated by microscale gas flow simulations and Pearson correlation analyses. The results showed that the CS1 sample significantly exceeded the W21 sample in terms of pore connectivity and permeability, with connected pore volume, throat count, and specific surface area being more than double that of the W21 sample. Pore–throat parameters are decisive for natural gas storage and transport. Additionally, based on seepage simulation and the pore–throat model, the specific influence of pore–throat structure parameters on permeability in volcanic reservoirs was quantified. In areas with well–developed fractures, gas seepage pathways mainly follow fractures, significantly improving gas flow efficiency. In areas with fewer fractures, throat radius has the most significant impact on permeability, followed by pore radius and throat length.

Investigation of pore structure evolution of Licorice extract during vacuum drying using Micro-CT 3D reconstruction

The micro-CT 3D reconstruction was applied to explore the pore structure evolution in vacuum drying of Licorice extract, and 8 kinds of pore structural characteristics were investigated. Results showed that during the first 3 h of drying, the extract remained in liquid form with low porosity (0.07 %-0.33 %) and pore number (100–139). Subsequently, the porosity sharply increased to 80.86 %, then slightly decreased and maintained at about 76.56 %. Meanwhile, the porosity distribution from the bottom to surface showed a rapid increase followed by a platform and a slight decrease. The pore number increased to 792 at the end. At 4 h drying, the throats were formed and its number continuously increased from 92 to 892. Concurrently, the pore connectivity first steeply raised and then declined. But the average length and diameter of throat decreased gradually. Overall, this method was successfully applied and contributed to better understand the drying process.

Heterogeneity properties and permeability of shale matrix at nano-scale and micron-scale

Heterogeneity of shale pores at nano-scale and micrometer-scale is of great significance to gas transport properties. In this study, the pore structure of shale samples from lower Silurian Longmaxi Formation in the Sichuan basin is investigated by field emission-scanning electron microscopy (FE-SEM) and x-ray micro-computed tomography (Xμ-CT) technology. Based on fractal theory, the lacunarity is introduced to describe the clustering degree of pores in shale matrix, which can compensate for the limitations of fractal dimension. Combining lacunarity with fractal dimension allows for quantification of subtle differences in pore spatial distribution. For FE-SEM images at nano-scales, the fractal dimension changes in a “U” shape, while lacunarity changes in a “∩” shape. For Xμ-CT images at micrometer-scale, both the fractal dimension and lacunarity change in a logarithmic function. Lacunarity at both nano-scale and micrometer-scale linearly decreases with the increase in fractal dimension. By three-dimensional (3D) pore network modeling analysis, the structure properties of the connected pores, such as the number of pores and throats, pore diameter, pore volume, pore surface, throat length, and coordination number, are quantitatively calculated, and these structure parameters show strong heterogeneity. The average coordination number of the connected pores ranges in 2.92–4.36. This indicates that these pores in shale matrix have poor connectivity. The permeability varies from 0.06 to 0.17 μm2 in two-dimensional (2D) Xμ-CT images but from 3.20 to 34.99 μm2 in a 3D structure. The permeability in the 3D structure is about two order higher in magnitude than that in the 2D Xμ-CT images.

Numerical Study of Cavitation Phenomenon in a Venturi Tube

This research aims to understand and numerically analyze the cavitation phenomenon that occurs in Venturi tubes with variations in throat length and pressure changes. This research uses Ansys Fluent 2023 R2 numerical simulation with venturi tube geometries of 25 mm, 30 mm, and 35 mm and pressures of 300,000, 600,000, and 900,000 Pa. A multiphase flow model with water liquid and water vapor is applied to predict cavitation using a mixture model. RANS steady state conditions with the k-ε turbulence model are used to solve the continuity, momentum, energy and volume fraction equations. The Schnerr-Sauer cavitation model calculates the phase transition between water-liquid and water vapor. Geometry varies by reference journal with different converging and diverging angles, outlined in tables and figures. 2D simulations are carried out using a pressure based solver with specified boundary conditions, using the Presto! for pressure solutions, and upwind and Quick schemes for discretization. The results of this research show that 1) Length throat 25 mm has the most stable distribution compared to 30 and 35 mm geometries at a pressure of 600,000 Pa. 2) The cavitation phenomenon is influenced by changes in geometry where at 35 mm geometry greater cavitation occurs in the area near the wall inlet convergent. 3) At a pressure of 900,000 Pa, the cavitation area that forms becomes larger and becomes a critical point in this journal.

Knowledge Extraction via Machine Learning Guides a Topology‐Based Permeability Prediction Model

AbstractThe complexity and heterogeneity of pore structure present significant challenges in accurate permeability estimation. Commonly used empirical formulas neglect its microscopic and topological characteristics, thus lacking accuracy and adaptability. While machine learning (ML) and deep learning (DL) models demonstrate promising performance, but encounter challenges of data availability, computational cost, and model interpretability. The present study aims to develop a more robust and accurate permeability prediction model via knowledge extraction from ML model. We first establish an ML model between permeability and the geometry‐topology characteristics of porous media using Extreme Gradient Boosting (XGBoost) algorithm. The data set used to fit ML model is prepared from 458 samples of different types of porous media. Using the SHapley Additive exPlanations (SHAP) value, the influence of each feature on permeability prediction is quantified. It is found that the closeness centrality (topology feature), tortuosity, porosity (macroscopic features) and throat diameter, throat length, pore diameter (pore network features) are vital for permeability prediction. Guided by partial dependence calculation, the unknown function relationship between permeability and the top six important features is established. The novel permeability prediction model incorporating topology feature improves the prediction accuracy and demonstrates strong applicability across diverse data sets. This new model presents an optimal balance between simplicity and performance, rendering it a compelling alternative for permeability prediction in porous media. The research provides a novel referable framework of knowledge extraction via ML to reveal the important features and establish the potential relationship that can be extended and applied in other research fields.

The impact of porous structure on oil–water two-phase flow under CO2 environment in continental shale reservoirs

CO2 applications for enhanced oil recovery and storage in continental shale reservoirs are promising, and there is a need to evaluate the impact of porous structure on oil–water two-phase flow under CO2 environment. In this study, first, digital cores of quartz-rich, carbonate-rich, and clay-rich shales are established using Focused Ion Beam Scanning Electron Microscopy scanning data processed through generative adversarial networks. Subsequently, the pore networks generated by digital cores are quantitatively analyzed using the generalized extreme value distribution. Finally, pore network modeling is carried out to elucidate the effect of porous structural differences on oil–water flow considering CO2 dissolution and capillary forces. The results show that quartz-rich shale, characterized by nanopore intergranular dominance and the highest pore network connectivity, demonstrates the highest relative permeability of the oil phase. Carbonate-rich shale exhibits intermediate relative permeability of oil phase, while clay-rich shale exhibits the worst. The dissolution of CO2 reduces oil–water interfacial tension and oil viscosity, enhances oil mobilization within nanopores, and notably increases the relative permeability of the oil phase. The permeability of the oil phase is governed by pore structure, displaying positive correlations with core heterogeneity, pore radius, coordination number, and throat length, and negative correlations with throat radius.

Study on the Influence of Geometric Parameters on Vibration Characteristics of Hydraulic Oscillator Used in Oil Drilling

Abstract Hydraulic oscillator is an important drilling equipment extensively used in petroleum extraction and drilling work. It generates vibration along the axis direction to drive the drilling tool to drill and the drilling effect largely depends on the axial impulsive loading and frequency of the hydraulic oscillator. However, few present studies have been conducted on the influence of variations in key geometric parameters on axial impulsive loading and frequency of hydraulic oscillators, and systematic analysis is still lacking. Optimization calculations were carried out on throat inner diameter, throat length, nozzle spacing, and nozzle angle of the hydraulic oscillator. The analysis results show that: The overall impact of throat length and nozzle angle changes on axial load is small, while throat inner diameter has the greatest impact on the axial load. The axial load is 375.78 N when throat inner diameter is 10 mm, which is 8 times larger than that when throat inner diameter is 20 mm. Moreover, the throat inner diameter is smaller, both the axial load and amplitude are greater. Nozzle spacing has a significant influence on the axial load within a narrow spacing range. As nozzle spacing increases, the axial load increases overall while the amplitude shows a decreasing trend. Particularly, when nozzle spacing exceeds a certain value, the axial load does not vary significantly.

Numerical investigation of hydroxyl radicals produced by a single bubble in jet pump cavitation reactor

Jet pump cavitation reactors (JPCRs) have significant potential to be used in water treatment applications. During their operation, the hydroxyl radicals generated by cavitation collapse produce a strong oxidation capacity, which is one of the key mechanisms in disrupting algal cells. In this paper, we investigate the hydroxyl radicals produced by single cavitation bubble in a JPCR. The numerical method includes a bubble dynamic model, molecular diffusion model, energy balance equation, and chemical reaction model for predicting the hydroxyl radical production. Additionally, the pressure distribution within a JPCR is tested and used to analyze the single-bubble performance. The effects of the JPCR operating conditions and structure parameters on hydroxyl radical production are further discussed. Our results indicate that, when the flow rate ratio is positive, the number of hydroxyl radicals is closely related to the development and collapse of the cavitation bubble and reaches a peak value under the critical condition. When the flow rate ratio is negative, the maximum production of hydroxyl radicals appears under backflow stagnation condition. In general, increasing the throat length–diameter ratio and diffuser angle encourages the production of hydroxyl radicals, whereas increasing the area ratio inhibits their generation.

Effects of the nozzle structure and fluidized gas composition on the gas-particle two-phase jet characteristic in a powder fuel scramjet

The interaction between nozzle design and fluidization gas composition significantly influences the dynamics within a powder fuel scramjet's combustion chamber. To investigate this relationship, an experimental study utilized high-speed shadow imaging technology to explore the macroscopic aspects of powder fuel injection. The investigation examined various convergence angles, nozzle throat lengths, and fluidized gas compositions. Key findings include: During jet development, powder fuel initially concentrates near the axis, with non-convergence angle nozzles exhibiting longer concentrated distribution periods than convergence angle conditions. Decreasing nozzle convergence angles lead to increased penetration distance, frontal velocity, and radial diffusion distance during the initial stages of jet development. Additionally, stable jet shapes show larger divergence angles as nozzle convergence angle decreases, with the largest divergence angle observed at α=60°. In the initial 0–7 ms of jet development, the powder fuel jet demonstrates greater penetration distance and frontal velocity under certain conditions. Moreover, penetration distance and frontal velocity increase with throat length from 7 to 20 ms, accompanied by changes in divergence angles. Specifically, at a throat length (l) of 2 mm, the near-field divergence angle measures 46.50°, and the far-field divergence angle is 22.25°. Conversely, at l=8mm, the near-field divergence angle is 33.49°, and the far-field divergence angle is 23.21°. The fluidization gas composition minimally affects jet penetration distance and frontal velocity during the initial 0–3 ms. However, due to hydrogen's low density, hydrogen/powder fuel jets exhibit shorter distances and velocities compared to nitrogen/powder fuel jets. Hydrogen fluidization also results in larger divergence angles, particularly in the near field. These findings underscore the importance of nozzle design and fluidization gas composition in optimizing scramjet performance and efficiency.

Quantitative characterization of 3D pore structures and percolation characteristics in bioturbated reservoir media based on X-ray micro-CT: a case study of the Neogene Sanya Formation in the Qiongdongnan Basin, Northern South China Sea

Organisms alter the primary texture of sediments, leading to alteration in petrophysical properties mediated by a textural and mineralogical contrast between burrow-fill and sediment host, which affects reservoir properties and fluid flow characteristics. In this article, in order to understand the microscopic pore structure and flow state of fluids in microscopic pores of bioturbated reservoirs, Ophiomorpha-bearing bioturbated reservoirs in the Neogene Sanya Formation of the Qiongdongnan Basin in the northern South China Sea were selected to research. Micro-CT was applied to scan selected core plugs, and a 3D pore structure model was established. The geometric characteristics of the microscopic pore structure were quantitatively and visually characterized by a modified maximal ball algorithm, and connectivity analysis of the pore structure was carried out. Numerical simulations of the percolation characteristics of the analyzed bioturbated reservoir samples were performed using digital core software (Avizo) and multi-physics field simulation software (Comsol). The results show that: (1) 3D pore structures reveal that pore volume, pore area, pore equivalent radius, throat area, throat equivalent radius and throat length have a large distribution range; among them, the pore volume has the largest distribution range, which can vary by six orders of magnitude, indicating that the pore size distribution of the bioturbated reservoir is uneven and has strong heterogeneous characteristics; (2) the connected pore structure is very complex, and as the equivalent radius of connected pore increases, the coordination number also gradually increases, the better the connectivity. Numerical percolation simulation results also suggested that larger connected pore space plays a key role in the effective permeability of the reservoir. This study has important implications for analyzing the modification effect of bioturbation on oil and gas reservoirs, and enhancing production and recovery in the study area.

The Effect of The Throat Length and The Hole Diameter in Throat Portion of The Venturi Nozzle on Aeration Efficiency

The Effect of The Throat Length and The Hole Diameter in Throat Portion of The Venturi Nozzle on Aeration Efficiency

Modelling and prediction of aeration efficiency of the venturi aeration system using ANN-PSO and ANN-GA

The significance of this study involves the optimisation of the aeration efficiency (AE) of the venturi aerator using an artificial neural network (ANN) technique integrated with an optimisation algorithm, i.e., particle swarm optimisation (PSO) and genetic algorithm (GA). To optimise the effects of operational factors on aeration efficiency by utilising a venturi aeration system, aeration experiments were conducted in an experimental tank with dimensions of 90cm×55cm×45cm. The operating parameters of the venturi aerator include throat length (TL), effective outlet pipe (EOP), and flow rate (Q) to estimate the efficacy of the venturi aerator in terms of AE. A 3–6-1 ANN model was developed and integrated with the PSO and GA techniques to find out the best possible optimal operating variables of the venturi aerator. The coefficient of determination (R2), root mean square error (RMSE), and mean absolute error (MAE) determined from the experimental and estimated data were used to assess and compare the performance of the ANN-PSO and ANN-GA modelling. It is shown that ANN-PSO provides a better result as compared to ANN-GA. The operational parameters, TL, EOP, and Q, were determined to have the most optimum values at 50 mm, 6 m, and 0.6 L/s, respectively. The optimised aeration efficiency of the venturi was found to be 0.105 kg O2/kWh at optimum operational circumstances. In fact, the neural network having an ideal design of (3-6-1) and a correlation coefficient value that is extremely close to unity has validated the results indicated above.

Research on Noise Reduction of Water Hydraulic Throttle Valve Based on RBF Neural Network and Multi-Island Genetic Algorithm

Excessive pressure drop within the internal flow channel of the water hydraulic throttle valve will generate severe noise. In order to reduce the noise of the throttle valve, in this paper, the model of the throttle valve was established, and the flow characteristics and acoustic characteristics of the valve were simulated. The simulation results showed that the parameters of the throat structure, such as the half angle, throat inlet angle and throat length, have a significant effect on the noise of the valve. Then, the three main structural parameters were used as optimization variables, and radial basis function (RBF) neural networks and multi-island genetic algorithms (MIGA) were used to reduce the noise of the valve. The approximate model of the relationship between the structural parameters of the valve and noise was established by RBF neural networks, and MIGA was used to optimize the approximate model. Finally, the optimal valve model was established based on the obtained optimal parameters, and its noise was analyzed through simulation and experiment. The research results indicated that the optimization method, which combines RBF Neural Network and MIGA, can effectively reduce the noise of hydraulic throttle valves.

Simulation of Internal Flow Field in Pulse Thruster Unit

Pulse thrusters are widely used in the attitude control and flight trajectory control of rotating ammunition and vertical launching ammunition, which use own pulse impulse to change the attitude and trajectory of the missile. This paper simulates the internal flow field of a double-layer pulse thruster unit (PTU). The internal flow field of the PTU is simulated at various temperatures based on the three-dimensional compressible N-S governing equations and k-ω SST turbulence model. In addition, the influence of nozzle throat length and divergence half-angle on the performance of pulse T-thruster is analyzed. The simulation results demonstrate that the thrust output error of the PTU is minimum, when the nozzle throat length of the internal pulse thruster is 38 mm. Moreover, the stability of the PTU is improved.

Pressure drop model of gas-liquid phase for Venturi scrubber in fog-annular flow

Venturi scrubber is widely used in wet dust removal. Its pressure drop performance determines the dust removal efficiency. The commonly used models, most of them are empirical ones, are hard to accurately predict the friction loss between the gas core and the liquid film near the wall, the proportion of the atomized droplets to the deposited liquid film, and the gas holdup, where the influence of the throat length on throttling and the local resistance formation mechanism were not discussed. Therefore, in this study, we established a pressure drop model for Venturi based on the theoretical derivation of two-phase flow and revision of local resistance pressure drop. It uses the similar theoretical method of straight pipe for Venturi, where the iterative method was employed to calculate the liquid-phase conversion coefficient which is related to the cross-flow ratio and the gas holdup. Meanwhile, the experiments and CFD simulations were carried out to validate the model and judge whether the local resistance should be considered. The results show that if the vena contracta extends out of the throat, the unconstrained expansion flow can cause the boundary layer separation, and the fluctuation of the two-phase flow in throat can induce Kelvin-Helmholtz instability, resulting in apparent energy loss. Accordingly, the critical throat length criterion was developed, and the pressure drop model was modified with the deviation less than 17.14%. It provides a scientific basis for establishing the universal two-phase theoretical pressure drop model of Venturi scrubber.

Study of the Flow Field and Permeability Characteristics in the Goaf using the OpenPNM Package

The roof-caving step scale goaf behind the working face is sensitive to the region’s spontaneous combustion and gas concentration distribution, including many rock block cracks and holes. A severe deviation from the dynamics of fluids in porous media by representative element volume (REV), leading to the results of Computational Fluid Dynamics (CFD) simulation, has a significant error. A heterogeneous two-dimensional pore network model was established to simulate the goaf flow accurately. The network was first created using the simple cubic lattice in the OpenPNM package, and the spatial distribution of the “O-ring” bulking factor was mapped to the network. The bulking factor and Weibull distribution were combined to produce the size distribution of the pore and throat in the network. The constructed pore network model was performed with single-phase flow simulations. The study determined the pore structure parameters of the pore network through the goaf’s risked falling characteristics and described the flow field’s distribution characteristics in the goaf. The permeability coefficient increases as pore diameter, throat diameter, pore volume and throat volume increase and increases as throat length decreases. The correlation between throat volume and permeability coefficient is the highest, which indicates that the whole throat is the main control factor governing the air transport capacity in the goaf. These results may provide some guidelines for controlling thermodynamic disasters in the goaf.

Design of short Venturi flow meters for incompressible and isothermal flow applications

The Venturi flow meter offers a range of measurement options for liquids, gas, steam, and slurries in piped systems. The main criteria for assessing Venturi performance include permanent pressure loss, discharge coefficient, relative pressure loss coefficient, and measurement accuracy. However, the extended length of Venturis, relative to other flow rate measuring instruments, can present limitations in some applications. Furthermore, the manufacturing of shorter Venturis requires less material and energy. This study addresses the challenge by developing shorter Venturi meters that adhere to established performance standards. Previous studies show that cone angles, the ratio of throat diameter to inlet diameter (β-ratio), and the throat length impact the performance of a Venturi. The scope of this research considers single-phase, incompressible and isothermal flows. The investigation focuses on the effect of cone angles for flows with Reynolds numbers ranging from 5000 to 10,000,000. Two axisymmetric Venturis, with a β-ratio of 0.7, were designed and evaluated against an ISO-5167 classical Venturi with the same β-ratio. Despite the ISO-5167 Venturi outperforming the others across the key criteria, a Venturi designed with a 40-degree convergent cone angle and a 10-degree divergent cone angle was 24.9 % shorter than the classical design and demonstrated similar performance to the ISO-5167 Venturi across Reynolds numbers from 100,000 to 10,000,000.

Characterisation of pore structure of bulk wheat mixed with dockage using X-ray micro-computed tomography and deep learning

Characterisation of pore structure inside grain bulks is essential for predicting the airflow resistance during grain drying and aeration. Herein, the 3D pore network of wheat mixed with different percentages of canola and dockage was characterised. The characterised parameters include pore size, throat length, coordination number, airpath length, and tortuosity. To simulate the grain storage condition, the loaded wheat mixtures were cured using wax at 110 °C. The images of the waxed wheat mixtures were produced by using a high-resolution X-ray micro-computed tomography (μCT) system at a resolution of 50 μm per pixel. The computed space distribution was based on the 3D medial axis analysis of each image stack using Dragonfly 4.1 software. The pore space was segmented using a deep-learning model with 90.1–98.0% accuracy. A watershed-based image algorithm was used to generate the pore network from the segmented pore space. The pore structure parameters were extracted from the pore network of each wheat mixture. Most pores were classified as mesopores (>99%) in a range from 62.5 to 4000 μm, with less than 1% classified as micropores (1–62.5 μm). The mean pore size of clean bulk wheat was 648 ± 403 μm with a mean throat length of 1115 ± 611 μm. In the mixtures with 10% canola, 5 and 10% wheat dockage, the mean pore size was reduced by 10%, 29%, and 17%, respectively, from clean wheat. Adding canola and dockage generally influenced the connectivity in the pore microstructure with changes in bulk porosity, tortuosity, airpath number, and length.

Pore-scale water–gas distribution and gas permeability of natural gas hydrate reservoirs in the South China Sea

Challenges in water drainage within natural gas hydrate reservoirs in the Shenhu area of the South China Sea, characterized by high clay content and strong hydrophilicity, significantly hinder natural gas recovery. Examining the effects of gas pressure and liquid/gas saturation on gas permeability reveals essential insights for increasing gas production potential. We report gas displacement experiments on clayey-silt sediment samples, alongside X-ray computed tomography imaging, that reveal critical findings: a notable increase in flow rate and permeability as displacement pressure nears compaction pressure, highlighting the role of pressure management in enhancing recovery; water displacement from varying pore sizes under different pressures, highlighting the influence of pore size on fluid dynamics, and structural changes, including microfracture formation and a significant fracture that enlarges total pore space by about 15%, which collectively suggest methods to improve gas flow and recovery. Moreover, our analysis identifies average throat length, fractal dimension, and succolarity as principal controls on gas permeability, indicating the substantial impact of microstructural properties on extraction efficiency. These outcomes offer valuable strategies for optimizing natural gas hydrate reservoir development in the South China Sea, emphasizing the need for meticulous pressure and saturation control and in applying a deep understanding of microstructural dynamics.

Velocity Augmentation Model for an Empty Concentrator-Diffuser-Augmented Wind Turbine and Optimisation of Geometrical Parameters Using Surface Response Methodology

Wind energy, renowned for cost-effectiveness and eco-friendliness, addresses global energy needs amid fossil fuel scarcity and environmental concerns. In low-wind speed regions, optimising wind turbine performance becomes vital and achievable by augmenting wind velocity at the turbine rotor using augmentation systems such as concentrators and diffusers. This study focuses on developing a velocity augmentation model that correctly predicts the throat velocity in an empty concentrator-diffuser-augmented wind turbine (CDaugWT) design and determines optimal geometrical parameters. Utilising response surface methodology (RSM) in Design Expert 13 and computational fluid dynamics (CFD) in ANSYS Fluent, 86 runs were analysed, optimising parameters such as diffuser and concentrator angles and lengths, throat length, and flange height. The ANOVA analysis confirmed the model’s significance (p < 0.05). Notably, the interaction between the concentrator’s length and the diffuser’s length had the highest impact on the throat velocity. The model showed a strong correlation (R2 = 0.9581) and adequate precision (ratio value of 49.655). A low coefficient of variation (C.V.% = 0.1149) highlighted the model’s reliability. The findings revealed a 1.953-fold increase in inlet wind speed at the throat position. Optimal geometrical parameters for the CDaugWT included a diffuser angle of 10°, concentrator angle of 20°, concentrator length of 375 mm (0.62Rth), diffuser length of 975 mm (1.61Rth), throat length of 70 mm (0.12Rth), and flange height of 100 mm (0.17Rth) where Rth is the throat radius. A desirability value of 0.9, close to 1, showed a successful optimisation. CFD simulations and RSM reduced calculation cost and time when determining optimal geometrical parameters for the CDaugWT design.