Ratio Contour Research Articles

Investigation of Transonic Flow Features in an Axial Flow Compressor Rotor

Numerical investigation of an axial flow rotor is carried out for its performance characterization and aerodynamic behavior during the design and off-design operating conditions. The study focuses on capturing the transonic flow features from the choke point (CP) to the near stall (NS) point in the rotor. This includes the analysis of passage shock structure, its movement in the blade passage with varying back-pressure, shock boundary layer interaction, tip leakage flow structure, and resulting losses. The study is carried out from 60 % to 100 % of the design speed using steady and unsteady RANS simulations. Three turbulence models, namely; SST, k-ε, and Reynolds stress models, are employed. The SST model predicted the closest approximation to the experimental data. The rotor aerodynamic performance is predicted in terms of total pressure ratio, efficiency, and flow contours. Unsteady analysis revealed that the primary and secondary tip leakage vortices, combined with the suction side tip corner separation, are the major instabilities near the stall region.

Magnetohydrodynamic free convection of nano-encapsulated phase change materials between two square cylinders: Mapping the thermal behavior using neural networks

The study focused on investigating the convective heat transfer of nano-encapsulated phase change suspensions in the presence of a non-uniform magnetic field within an annuli space between two square cylinders. The principal equations for the fluid flow and phase change heat transfer were formulated as partial differential equations and then represented into dimensionless format. The finite element method was used to solve these equations and simulate the free convection heat transfer. The effect of various factors, including Hartmann, Rayleigh, Eckert and Stefan numbers, geometry aspect ratio, nanoparticles’ concentration, and fusion temperature, on the heat transfer rate was examined. A neural network was also introduced and trained to establish the connection between the control parameters (inputs) and the heat transfer rate (output). The outcomes were presented in the form of the modified Nusselt number, along with isotherms, heat capacity ratio (phase change) contours, and streamlines. The results demonstrated that the neural network could accurately predict the heat transfer rate and provide a comprehensive map of heat transfer with respect to the control parameters. Nano-Encapsulated Phase Change Materials (NEPCMs) can be considered as a new type of nanofluids, in which the nanoparticle consists of a core and a shell. The core part is made of a Phase Change Material (PCM) which can undergo solid-liquid phase change at a certain fusion temperature, and absorb/release a significant amount of energy due to latent heat of the phase change.

Upper crustal Vp/Vs ratios along the northern East Pacific Rise derived from downward-continued streamer data

SUMMARY Multi-channel seismic (MCS) imaging has been extensively used to investigate fast-spreading East Pacific Rise (EPR) crustal compressional wave velocity (Vp) structure and tectono-magmatic behaviors. However, its upper oceanic crust’s shear wave velocity (Vs) profile has remained a rarity. We first confirm that additional offset ranges can be derived for traveltime picking from downward-continued MCS data in fast-spreading tectonic settings for both early-arrival P and S waves. We then inverse independent 2-D Vp and Vs structures along a ∼80-km-long along-axis stretch of the northern EPR. The resulting Vp/Vs ratio exhibit that the upper crust comprises pillow lavas, transition zone and sheeted dykes. The average thickness of pillow lavas is ∼125 m, with Vp increasing from ∼2.8 to 3.2 km s−1 and Vs from ∼1.2 to 1.5 km s−1. The lava unit with a transition zone has high Vp/Vs ratios (∼2.1 ± 0.2), indicating that fracturing and alteration are variable but pervasive. The average thickness of the transition zone is ∼400 m, with Vp increasing from ∼3.2 to 5.3 km s−1 and Vs from ∼1.5 to 2.8 km s−1. The pillow lavas and the transition zone constitute the layer 2A with an average thickness of ∼525 m. The boundary of layer 2A/2B can be defined using a Vp/Vs ratio contour of 1.9. The layer 2B exhibits lower Vp gradients (∼1.51 s−1), Vs gradients (∼1.30 s−1) and Vp/Vs ratios (∼1.8–1.9) compared to the layer 2A (∼4.65 s−1, ∼2.98 s−1 and ∼2.1 ± 0.2). Porosity variation and crack morphology are critical in controlling the seismic velocities of layer 2A. The strong lateral heterogeneity of the Vp/Vs ratios indicates hydrothermal signatures in the upper crust. The high Vp/Vs anomalies indicate fluid pathways into and out of the oceanic upper crust. This study demonstrates that the Vp/Vs ratio can be obtained from seismic tomography of downward-continued streamer data and used as a reference to investigate the crustal structure and hydrothermal activities along fast-spreading ridges.

Aggregate size characterisation and porosity analysis of granular mixtures

ABSTRACT This paper aims to explore the correlate relationship between particle size composition and porosity of particles and reveal its influence mechanism. First, aggregate particles were divided into coarse aggregate, medium aggregate and fine aggregate. Combination of the particle size ratio and mixing proportion of each grade aggregate were used to characterize the particle size distribution. Second, a mixture proportion triangular coordinate system was proposed; and a series of void ratio contour maps of granular mixtures were plotted in the coordinates based on results of the discrete element numerical simulation test. Finally, correlation between mixture composition and porosity has been analysed. It was found that (1) The void ratio of mixtures with different particle size ratio combinations is mainly different from the size and distribution. (2) Both proportion and particle size composition of coarse aggregate are main factors affecting the change of porosity. (3) For mixtures with the maximum particle size of 16 mm, various particle size ratios within that definition of coarse aggregate are possible. Suitable combination schemes of particle size ratio for each grade of aggregate are recommended for the gradation evaluation and design. (4) The relationship between gradations and voids for the granular mixtures has been established and quantitatively characterised..

Buckling Enhancement Analysis of Auxetic Laminated Rectangular Plate under Uniaxial Compression

The buckling enhancement of the negative Poisson’s ratio (NPR) effect on a laminated plate under uniaxial compression with an in-plane translational restraint is investigated in this paper. According to the buckling equation of an orthotropic plate under biaxial compression, the critical buckling load of an NPR-laminated composite under uniaxial compression can be increased due to the induced tension force on the unloaded direction. Instead of layer angles and stacking sequence, the NPR envelope and buckling load enhancement are studied using lamination parameters in this paper. The Poisson’s ratio contours are given in the feasible region of membrane lamination parameters. The results show that the negative Poisson’s ratios are more sensitive to V3A, which represents the unbalance degree of the laminate. Furthermore, the buckling loads for various Poisson’s ratio layups are investigated, and it is concluded that the buckling load increases with a decrease in Poisson’s ratio for the laminated rectangular plate considering in-plane translational restraint. Finally, the inverse problem of deciding the laminate configuration to target the lamination parameters is solved using the particle swarm optimization (PSO) algorithm.

Numerical Study on a Supersonic Flow around a Bullet

In this research paper, a numerical analysis in Computational Fluid Dynamics uses the Finite Volume Method to visualize the external flow characteristics over a bullet speeding at Mach 2.0. The simulation results evaluate the experimental drag coefficient of the supersonic bullet airflow in a wind tunnel. The numerical simulation assumes that the inviscid model remains non-rotating. The generation of the mesh geometry varies between Coarse, Medium, and Fine types, and proper selection of the grid density improves the accuracy of the numerical result. The Fine Quadrilaterals mesh of 150,000 elements achieved considerable punctuality along with the numerical method of the second-order linear differential equations. The drag coefficient value of 0.222 gives a 0.9 percent error relative to the attained experiment value. The Mach number, pressure ratio, and flow simulation velocity contours obtained with ANSYS FLUENT software represent the validation of the experimental data with numerical analysis method in a typical fluid mechanics problem.

Photolithographic microfabrication of hydrogel clefts for cell invasion studies.

Invasion of migrating cells into surrounding tissue plays a key role in cancer metastasis and immune response. In order to assess invasiveness, most in vitro invasion assays measure the degree to which cells migrate between microchambers that provide a chemoattractant gradient across a polymeric membrane with defined pores. However, in real tissue cells experience soft, mechanically deformable microenvironments. Here we introduce RGD-functionalized hydrogel structures that present pressurized clefts for invasive migration of cells between reservoirs maintaining a chemotactic gradient. Using UV-photolithography, equally spaced blocks of polyethylene glycol-norbornene (PEG-NB) hydrogels are formed, which subsequently swell and close the interjacent gaps. The swelling ratio and final contours of the hydrogel blocks were determined using confocal microscopy confirming a swelling induced closure of the structures. The velocity profile of cancer cells transmigrating through the clefts, which we name 'sponge clamp', is found to depend on the elastic modulus as well as the gap size between the swollen blocks. The 'sponge clamp' discriminates the invasiveness of two distinct cell lines, MDA-MB-231 and HT-1080. The approach provides soft 3D-microstructures mimicking invasion conditions in extracellular matrix.

Performance Modeling and Simulation for Wastewater Collection Networks

This study develops a framework for asset management strategy of wastewater collection networks comprised of three interconnected decision-making layers: (1) Visions & Values, (2) Function, and (3) Performance, which are set according to the established concepts of strategic targets, policy levers, sustainability and life cycle. The asset management strategy framework is implemented and validated through demonstration of functionality and value by using the wastewater collection networks of three utilities in Ontario, Canada, to drive management simulations. A borrowing management strategy is used to benchmark the utilities against each other in terms of infrastructure, sociopolitical, and financial performance over a 100-year benchmarking period. It is found that a borrowing management strategy can enable the utility to accelerate their capital works, reduce the volume of inflow and infiltration and their associated expenses and sustainably meet their strategic targets over the life cycle of the assets. Using contour plots, the impact of maximum debt capacity on two infrastructure and financial benchmarking performance indicators is also investigated to explore the “optimal” combination of allowable fee hikes and preferred rehabilitation rates. Furthermore, using a borrowing management strategy, a business case for asset management of wastewater collection networks is developed to explore the “optimal” combination of allowable fee-hike and rehabilitation rates, using a developed inflow and infiltration expenditures (I&IEx) saving ratio contour plots. The results indicate that a borrowing management strategy competes as long as the combinations of allowable fee-hike and preferred rehabilitation rates lead to a positive value of I&IEx saving ratio.

Simulation of mixed-convection of water and nano-encapsulated phase change material inside a square cavity with a rotating hot cylinder

Nano-encapsulated PCM consists of a solid shell and a phase change material (PCM) in the core that improves the thermal properties of base fluids. The heat capacity of the nanofluid increases due to the latent heat of the NEPCM core and the heat transfer rate increases dramatically. Also, a phase change occurs in a certain range of temperature. In the present study, the core and shell of NEPCM are n-nonadecane and polyurethane, respectively. Mixed convection of water-NEPCM is simulated inside a square chamber with cold walls and a hot rotating cylinder in the center. Coupled PDE equations are solved by the SIMPLE algorithm and developing C++ code. The parameters of Grashof number, Reynolds number, intensity of stored energy in the core of NEPCM (χ), and fusion temperature (θf) have been studied on the flow pattern, temperature contour, heat capacity ratio (Cr) contour, and Nusselt number. Based on this study it can be concluded that in general the optimal state of θf is in moderate values or especially numbers close to 0.5 and at this range of θf, χ reduction can enhance Nusselt number more. Also, at high Gr number by increasing Re number, heat transfer rate reduces. The results also show that adding NEPCM can increase the Nusselt number by more than 13%.

Automatic prediction of left cardiac chamber enlargement from chest radiographs using convolutional neural network.

To develop deep learning-based cardiac chamber enlargement-detection algorithms for left atrial (DLCE-LAE) and ventricular enlargement (DLCE-LVE), on chest radiographs METHODS: For training and internal validation of DLCE-LAE and -LVE, 5,045 chest radiographs (CRs; 2,463 normal and 2,393 LAE) and 1,012 CRs (456 normal and 456 LVE) matched with the same-day echocardiography were collected, respectively. External validation was performed using 107 temporally independent CRs. Reader performance test was conducted using the external validation dataset by five cardiothoracic radiologists without and with the results of DLCE. Classification performance of DLCE was evaluated and compared with those of the readers and conventional radiographic features, including cardiothoracic ratio, carinal angle, and double contour. In addition, DLCE-LAE was tested on 5,277 CRs from a healthcare screening program cohort. DLCE-LAE showed areas under the receiver operating characteristics curve (AUROCs) of 0.858 on external validation. On reader performance test, DLCE-LAE showed better results than pooled radiologists (AUROC 0.858 vs. 0.651; p < .001) and significantly increased their performance when used as a second reader (AUROC 0.651 vs. 0.722; p < .001). DLCE-LAE also showed a significantly higher AUROC than conventional radiographic findings (AUROC 0.858 vs. 0.535-0.706; all ps < .01). In the healthcare screening cohort, DLCE-LAE successfully detected 71.0% (142/200) CRs with moderate-to-severe LAE (93.5% [29/31] of severe cases), while yielding 11.8% (492/4,184) false-positive rate. DLCE-LVE showed AUROCs of 0.966 and 0.594 on internal and external validation, respectively. DLCE-LAE outperformed and improved cardiothoracic radiologists' performance in detecting LAE and showed promise in screening individuals with moderate-to-severe LAE in a healthcare screening cohort. • Our deep learning algorithm outperformed cardiothoracic radiologists in detecting left atrial enlargement on chest radiographs. • Cardiothoracic radiologists improved their performance in detecting left atrial enlargement when aided by the algorithm. • On a healthcare-screening cohort, our algorithm detected 71.0% (142/200) radiographs with moderate-to-severe left atrial enlargement while yielding 11.8% (492/4,184) false-positive rate.

Lidar Observations of Instability and Estimates of Vertical Eddy Diffusivity Induced by Gravity Wave Breaking in the Arctic Mesosphere

AbstractOn the night of 18–19 October 2018, sodium resonance lidar measurements show the presence of overturning in the mesospheric sodium layer. Two independent tracers, sodium mixing ratio and potential temperature, derived from resonance and Rayleigh lidar measurements, reveal that vertical spreading of the sodium mixing ratio contours and a layer of convective instability coincide with this overturning. Analysis of lidar measurements also reveals the presence of gravity waves that propagate upward, are saturated, and dissipate at the height of the convective instability. The vertical spreading is analyzed in terms of turbulent diffusive transport using a model based on material continuity of sodium. Estimates of the turbulent eddy diffusion coefficient, K, and energy dissipation rate, ε are derived from the transport model. The energy dissipated by the gravity waves is also calculated and found to be sufficient to generate the turbulence. We consider three other examples of overturning, instability and spreading on the nights of: 17–18 February 2009, 25–26 January 2015, and 8–9 October 2018. For all four events we find that the values of K (∼1,000 m2/s) are larger and the values of ε (∼10–100 mW/kg) are of similar magnitude to those values typically reported by ionization gauge measurements. These examples also reveal that higher levels of turbulent mixing are consistently found in regions of lower stability.

Indoor Wavelet OFDM VLC-MIMO System: Performance Evaluation

Both light emitting diode (LED) characteristics for illumination and communication simultaneously have made visible light communication-orthogonal frequency division multiplexing (VLC-OFDM) a strong competitive to radio frequency (RF). In this juncture, to improve signal to noise ratio (SNR) and coverage contour, the wavelet-OFDM is suggested for indoor VLC systems. In this paper, a wavelet VLC-OFDM is proposed for imaging multiple-input multiple-output (MIMO) systems. The proposed wavelet-OFDM is exploited for a hybrid space-frequency domain pre-equalization technique instead of the traditional fast Fourier transform (FFT)-OFDM technique. The Meyer filter is selected and employed in the proposed technique. A comparable achievement is elaborated for several numbers of channels to achieve the enhanced performance in terms of bit rate and coverage contour. In addition, a useful comparison is executed between our wavelet VLC-OFDM and the traditional FFT-OFDM for a hybrid space-frequency domain pre-equalization technique. The simulation results emphasize the superiority point of wavelet VLC-OFDM MIMO system by improving the coverage contour by ~20% over the traditional OFDM at a 10−3 bit error rate (BER) target. Hence, the proposed technique can be potentially executed in indoor VLC-MIMO systems.

Design of a Broadband Circularly Polarized Antenna by Using Axial Ratio Contour

A novel method of using axial ratio (AR) contour to design a broadband circularly polarized (CP) antenna is presented in this letter. By resolving a radiated CP wave into two orthogonal far-field components, the resulted AR will be determined by the radiated power and phase differences between the two orthogonal components. Therefore, a series of AR contours can be obtained for different AR values of the radiated wave. In the AR contour, details of phase advance, phase lag, power advance, and power lag can be simultaneously observed along with the resulted AR. Based on these analyses, the AR contour is first utilized to directly design a broadband CP antenna instead of using the traditional AR versus frequency curve to achieve optimal AR bandwidth. Compared to the traditional AR curve, the method of using AR contour to design CP antenna is more effective and informative. The designed broadband CP antenna was also fabricated and measured for the final performance verification.

On the Variation of the Effect of Natural Gas Fraction on Dual-Fuel Combustion of Diesel Engine Under Low-to-High Load Conditions

Natural gas-diesel dual fuel (NDDF) engine has the potential to significantly reduce carbon dioxide (CO2) and particulate matter (PM) emissions, while retaining diesel engine’s high efficiency and reliability. The operation and performance of NDDF engine depend on natural gas energy fraction (%NG), which ranges from low %NG, where diesel fuel provides most of the combustion energy, to high %NG where diesel fuel is used only to initiate combustion. Although pertaining published studies demonstrated that the effect of %NG on the combustion performance and emissions of NDDF engine depend upon the engine load, none of these studies discussed the reasons behind this dependence. The present study attempts to shed light on this issue by experimentally and numerically investigating the effect of different %NGs on NDDF engine under different load conditions. Both experimental and numerical results revealed that the peak pressure rise rate (PPRR) first increases and then drops with increasing %NG under all load conditions. The calculated local equivalence ratio and charge temperature contours showed that increasing %NG to a certain limit increases local equivalence ratio inside the ignition kernel which implies that more premixed natural gas – air mixture participates in reactions during the premixed combustion stage. This results in an increased flame temperature and higher PPRR right after ignition. However, increasing %NG beyond this range decreases local equivalence ratio inside the ignition kernel which leads to lower PPRR. Increasing %NG retards the combustion phasing at low to medium load conditions. However, increasing %NG generally advances the combustion phasing under medium to high load conditions due to the fact that the flame propagation speed of natural gas – air mixture increases with %NG at medium to high load conditions. Methane emissions grow with increasing %NG under all examined engine load conditions. However, this growth becomes much smaller under medium to high engine load conditions. Increasing %NG significantly increases GHG emissions under lower load conditions. However, using advanced diesel injection timing decreases GHG emissions of NDDF engine under lower load conditions. Increasing %NG decreases GHG emissions by 6 to 11% under medium to high load conditions.

Pancreas-visceral fat CT value ratio and serrated pancreatic contour are strong predictors of postoperative pancreatic fistula after pancreaticojejunostomy

BackgroundOur aim is to elucidate the true preoperative risk factors for postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy (PD), making it possible to select POPF high-risk patients preoperatively regardless of intraoperative pancreatic consistency judged by the surgeon’s hand.MethodsAmong the 298 patients who underwent PD with pancreaticojejunostomy from 2007 to 2016, 262 patients had preoperative CT configurations that could be precisely evaluated. Risk factor analyses were conducted using various perioperative factors, including preoperative CT findings, such as CT values of the pancreas, pancreas-visceral fat CT value ratio and pancreatic outer contour. Pancreatic outer contour was further divided into smooth- (smooth interlobular) and serrated-type contours (feathery, irregular interlobular) by preoperative CT.ResultsIn terms of the incidence of POPF, among the 262 patients, POPF grade B/C was found in 27 (10.3%): grade B in 23 (8.8%) and grade C in 4 (1.5%). According to multivariate analysis, a high pancreas-visceral fat CT value ratio (p = 0.002), serrated-type contour (p = 0.02) and no history of chemoradiotherapy (p = 0.019) were identified as independent risk factors for POPF grade B/C. Even in patients with soft pancreas, the incidence of POPF grade B/C was 0% (0/57) in patients with a pancreas-visceral fat CT value ratio of less than − 0.4 and smooth-type contour, whereas the incidence was markedly high (45.0%, 9/20) in patients with a pancreas-visceral fat CT value ratio of − 0.4 or greater and serrated-type contour, indicating that patients with soft pancreas should be categorized into POPF high-risk and low-risk groups according to preoperative CT scan results.ConclusionsThe pancreas-visceral fat CT value ratio and serrated-type pancreas are useful markers to preoperatively identify true POPF high-risk groups in patients undergoing PD, regardless of the pancreatic texture judged intraoperatively.

Roof Deformation Associated with Mining of Two Panels in Steeply Dipping Coal Seam Using Subsurface Subsidence Prediction Model and Physical Simulation Experiment

This research investigates roof deformation and failure characteristics, as well as mechanical interaction between the panels of the roof strata above two adjacent working faces in a steeply inclined coal seam. Physical modeling with photogrammetry measurement method has been employed in this investigation. The movement of roof strata and section pillar, as well as the stratum morphological characteristics, was quantitatively analyzed. Results show that the roof movement direction above the two panels has zoning characteristics, especially in the lower panel. Roof migration in the lower panel of the working face is larger than that in the upper panel. The roof to floor closure perpendicular to the seam direction is larger than the sliding along the seam. The maximum roof concave and convex bending occurred at the middle and upper parts of both panels; the roof bending in the upper panel mining area indicates a larger mining disturbance induced by lower panel mining. The void ratio contour of the lower panel is an asymmetrically arched shape, which is different from that of the upper panel area. The higher roof strata above the upper panel exhibit separation and breaking, whereas the lower roof exhibits compression due to mining in lower panel. The section pillar is compressed and slides slightly, which aggravates the mechanical interaction between the panels and increases the caving height of the roof over the lower panel and the periodic weighting intensity.

Optimization of Cutting Parameters for Trade-off Among Carbon Emissions, Surface Roughness, and Processing Time

As the manufacturing industry is facing increasingly serious environmental problems, because of which carbon tax policies are being implemented, choosing the optimum cutting parameters during the machining process is crucial for automobile panel dies in order to achieve synergistic minimization of the environment impact, product quality, and processing efficiency. This paper presents a processing task-based evaluation method to optimize the cutting parameters, considering the trade-off among carbon emissions, surface roughness, and processing time. Three objective models and their relationships with the cutting parameters were obtained through input–output, response surface, and theoretical analyses, respectively. Examples of cylindrical turning were applied to achieve a central composite design (CCD), and relative validation experiments were applied to evaluate the proposed method. The experiments were conducted on the CAK50135di lathe cutting of AISI 1045 steel, and NSGA-II was used to obtain the Pareto fronts of the three objectives. Based on the TOPSIS method, the Pareto solution set was ranked to find the optimal solution to evaluate and select the optimal cutting parameters. An S/N ratio analysis and contour plots were applied to analyze the influence of each decision variable on the optimization objective. Finally, the changing rules of a single factor for each objective were analyzed. The results demonstrate that the proposed method is effective in finding the trade-off among the three objectives and obtaining reasonable application ranges of the cutting parameters from Pareto fronts.

A study of the relationship between nuclear contour thickening, nuclear enlargement and human papillomavirus infection in squamous cells.

To investigate the relationship between the morphological features of nuclear enlarged cells and human papillomavirus (HPV) infection in negative for intraepithelial lesion or malignancy (NILM) and atypical squamous cells of undetermined significance (ASC-US). In total, 128 Papanicolaou specimens comprising 41 ASC-US cases and 87 NILM cases were examined. Cell morphological analysis was performed using both area ratio (nuclear area in cells with nuclear enlargement/nuclear area in normal intermediate cells) and nuclear contour thickening. High-risk HPV was detected using the Uniplex E6/E7 polymerase chain reaction assay and logistic regression analyses of factors related to high-risk HPV infection were performed. Nuclear contour thickening was present in 57.7% (64/111 cells) of high-risk HPV positive cases and 21.8% (69/317 cells) of high-risk HPV negative cases. There was a statistically significant association (P=0.01) between high-risk HPV infection and nuclear contour thickening. Nuclear contour thickening was approximately one-third higher in NILM cases than in ASC-US cases (odds ratio, 0.371; 95% confidence interval, 0.208-0.662) and three times higher in high-risk HPV-positive cases than in high-risk HPV-negative cases (odds ratio, 2.831; 95% confidence interval, 1.591-5.039). Our results suggest that nuclear contour thickening in nuclear enlarged cells in NILM and ASC-US cases may be a cellular finding associated with HPV infection.

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.

Contour Extraction and Quality Inspection for Inner Structure of Deep Hole Components

This paper focuses on the contour extraction for the inner wires of a kind of deep hole component to achieve a high-accuracy inspection. The vision system consisting of a camera and an endoscope is developed to acquire high-quality images of the internal structure. For the acquired images, a contour extraction method is proposed, which could be divided into the following steps. First, the start points of wires referred as the prior information on the component are obtained with a predefined filter, and on the basis, several regions of interest (ROIs) are defined. Second, the multiscale probability of boundary operator is utilized to detect edges in the ROIs. Third, a Brownian motion model is established to calculate the connectivity between edges. The prior information obtained previously is used again to determine the probabilities of the edges belonging to the contours. Finally, the symmetric ratio contour method is used to form the wires’ contours with the edges. In the proposed method, the edges belonging to the wires’ contours are enhanced by making full use of the prior information, resulting in the improvement in accuracy and real-time performance. As evidenced by the experiments, the proposed method can efficiently extract the inner wires’ contours from the component’s image with low-contrast conditions, noises, and shadows.