Fluid In Tube Research Articles

Biomarker collection from the Caribbean Hispanic families from Dominican Republic and New York.

AbstractBackgroundGenetic Studies of Alzheimer’s Disease in Caribbean Hispanics (CH) has been ongoing for over 20 years. Our primary goal was to identify genes in large well‐phenotyped, multiplex families, and sporadic cases and controls. This longitudinal collection of data represents a unique resource for the scientific community. The project is led by collaborators in the United States (US) and the Dominican Republic (DR). For the past three years, our efforts have been centered on the collection of cerebrospinal fluid (CSF), plasma, serum and Paxgene tubes for RNA to study core biomarkers. Collection of blood samples for DNA to conduct genetic analyses is also ongoing.MethodThe cohort consisted of participants aged 50 and older from the DR, including those living in the New York City area, willing and able to provide a blood and CSF samples. Interviewers in the DR were trained to collect data, blood samples and CSF. DNA samples were sent overnight to Columbia university (CU) for processing. CSF, Paxgene tubes, serum and plasma samples were processed in the DR and stored at ‐80F for batch shipping to CU. APOE genotyping was conducted in the US. Biomarkers, metabolomics, and proteomics data was generated at Columbia University. Methylation assays from Paxgene was conducted at Uniformed Services University (USUHS).ResultWe have databased a total of 1899 individuals with plasma samples, 1707 with Paxgene, 1731 with serum and 203 with CSF. Blood samples from 1079 participants have genome wide arra, whole genome sequencing and APOE genotyping. 192 CSF samples have proteomics completed, 153 CSF samples have metabolomics data and 742 have plasma biomarkers (Ab40, Ab42, T‐tau, P‐tau181, NFL and GFAP)).ConclusionSample collection for genetic studies in developing countries present important logistical challenges. Despite these challenges, sample quality is comparable to those collected in New York. Biomarkers from CSF, serum and plasma can give us a closer look into underrepresented populations such as Caribbean Hispanics. Results suggest that similar protocols can be successful in Latin America. Future work will augment the biosample collection of the cohort by collecting samples from additional subjects.

Thermal performance study of heat exchanger by applying nanofluids

The current research proposes a numerical investigation in the triple tubular concentric heat exchanger (TTCHE). Numerical validations of the TTCHE's performance in parallel flow are made. Using the CFD commercial software ANSYS 19.2, temperature variations for the flow of three separate fluids normal-hot–cold (NHC) and cold-hot-normal (CHN) estimates are made through the triple tube's length. When water is supplied, hot fluid always runs through the middle tube, while cold and normal fluid alternately flows along the other tubes. The outside pipe, middle pipe, and inner pipe have respective diameters of 0.1015 m, 0.076 m, and 0.05 m; the tube is 4 m long. The thickness is 1.50 mm of each tube. Then, employing Al2O3 and TiO2 nanofluids in 0.01 %, 0.03 %, 0.05 %, and 0.07 % wt. fractions instead of normal fluid in both scenarios (CHN & NHC), the computed OHTC enhanced upto 19.89 % and 19 % by employing water based Al2O3 and TiO2 nanofluids. The results showed that the HTC increases as the wt. fraction of nanofluids increases. Compared to other arrangements, the NHC has better performance.

Optimal evaluation of photovoltaic-thermal solar collectors cooling using a half-tube of different diameters and lengths

Photovoltaic Thermal Solar Collectors (PVTs) combine the advantages of photovoltaic (PV) and solar thermal collectors to produce electricity and heat simultaneously. This study proposes a numerical model to investigate the effectiveness of using half-circular tubes to improve thermal conductivity and increase the interaction area between PV panels and tubes. This enhances heat transfer from the PV panels to the working fluid (water) circulating through the thermal absorber. Additionally, the integration of phase change material (PCM) is explored to further boost thermal conductivity and generate hot water. The research focuses on modeling the cooling of solar PV panels using copper half-tubes. The PV panels measure 870 × 665 × 3 mm and generate a power output of 100 W. The study examines the impact of key variables such as tube diameter (three standard sizes: 10, 12, and 15 mm) and fluid flow rate (0.008 to 0.04 kg/s). Solar radiation equations are incorporated, and the finite volume approach, implemented in the ANSYS 19.0 software's CFX modeling framework, is used as the underlying methodology. The investigation culminates in an optimization process to determine the optimal operating conditions for the PV system. The results show that the highest electrical efficiency (13.15%) is achieved at a flow rate of 0.04 kg/s for 15 mm diameter tubes and 7 tubes in total. The peak thermal efficiency (74.28%) is observed under the same conditions. In conclusion, this study contributes to the understanding of enhancing PV/T system performance through innovative thermal management strategies and provides valuable optimization recommendations for achieving improved electrical and thermal efficiencies.

Microdialysis as a sampling tool for the chemotherapeutic agent Doxorubicin

Doxorubicin is a chemotherapeutic agent used for more than fifty years to treat a great variety of cancers in both children and adults. Despite hereof, pharmacokinetic knowledge is almost solely based on systemic plasma concentrations. Microdialysis is a catheter-based pharmacokinetic sampling tool enabling simultaneous target site sampling of unbound molecules of interest. The aim of this study was to thoroughly evaluate the feasibility of applying microdialysis for sampling of Doxorubicin in both in vitro experiments and an in vivo setting. Doxorubicin relative recovery by gain and by loss was tested for different catheter types, perfusion fluids, concentrations and collection vials. Adsorption tests revealed polystyrene/santoprene vials to be the biggest contributor of unwanted adsorption between Doxorubicin and the microdialysis equipment, and confirmed LoBind Eppendorf tubes to be a suitable alternative. The methodological combination of polyamide membranes, saline as perfusion fluid and LoBind Eppendorf sampling tubes demonstrated no statistically significant differences for relative recovery by gain and by loss, and the relative recovery was also found to be concentration independent. We conclude, that a proper microdialysis set-up can be used to collect samples containing concentrations of the chemotherapeutic drug Doxorubicin in vitro and in vivo, which encourage future pharmacokinetic studies to evaluate current treatment regimens to find the most effective and least toxic anti-neoplastic treatment for the patients.

Combined passive enhancement techniques improve the thermal performance of latent heat storage system: A design anomaly?

Poor heat transfer rate due to low thermal conductivity of phase change material limits the wide application of latent heat storage (LHS) systems. Thermal performance enhancement techniques can be potential methods to address this major limitation of LHS systems. In this context, the present numerical study examines the individual and cumulative impact of two passive heat transfer enhancement techniques (the orientation of the domain and position of the heat transfer fluid (HTF) tube) on the thermal performance of the latent heat storage (LHS) system consisting of high-temperature (HT) phase change medium (PCM). The individual effect of orientation decreases the charging duration of θ = 0° (horizontal configuration) by 10.5 %, 15 %, and 19.04 % than θ = 30°, θ = 60° and θ = 90° (vertical configuration), respectively. However, the discharging duration remains unchanged for all inclinations (11.5–12 h). The individual effect of eccentricity decreases the charging duration of horizontal (θ = 0⁰, ey = −5 mm,-10 mm,-20 mm) system by 6.25 %,12.8 %, and 18.75 % than concentric horizontal (θ = 0°, ex = ey = 0) system. Moreover, the combined effect of orientation and eccentricity (θ = 0⁰,ey = −5 mm,-10 mm,-20 mm) reduces charging duration by 28.75 %, 33.33 %, and 38.1 % than vertical concentric domain (θ = 90°, ex = ey = 0), respectively. However, eccentricity in vertically upward and downward directions increases the discharging duration compared to the concentric domain. Hence, the combined effect results in a design anomaly for HT-LHS system. The charging and discharging performances are observed to be predominantly sensitive to the Rayleigh number than the Reynolds number.

Machine learning‐assisted analysis and prediction for the thermal effect of various working fluids in a vortex tube

AbstractWith the widespread application of vortex tube in various fields, it becomes essential to quantitatively explore the separation effect of different fluids (natural fluids, hydrocarbons, etc.) within the vortex tube and to promote its utilization. A new approach has been developed in this study to establish quantitative models for predicting the thermal effects of different fluids in a vortex tube. These models are based on both the macro properties of the working fluid and micro molecular descriptor through a molecular scale. A dataset of 11 numerical simulation results of hydrocarbons and hydrofluorocarbons refrigerants is employed. Three operating conditions, 10 property parameters, and 115 molecular descriptors are screened and identified using random forest feature analysis. Two types of models (micro and macro) have been developed by employing artificial neural network (ANN) modeling techniques. In the result, four key influencing fluid property parameters (the specific heat ratio γ, the multiplication of heat capacity and the molar weight cp·M, the kinematic viscosity ν, and the thermal conductivity λ) and nine molecular descriptors in affecting the thermal effect are identified and respectively chosen as the input in the macro and the micro ANN model establishment. Both types of developed models show a high correlation coefficient (R > .999) and a comparatively low mean square error (MSE). When R600 is employed in the validation, most of the relative error is less than 10%, suggesting both types of models can work effectively in predicting the thermal effect for other fluid. The findings contribute to a deeper understanding of the thermodynamic effect of vortex tubes and provide a valuable tool for selecting and optimizing working fluids in various applications.

Predication of entropy generation rate in a concentrating photovoltaic thermal system with twisted tube turbulator using Boosted regression tree algorithm

Efficient energy conversion and utilization remain paramount in addressing the growing energy demand and environmental concerns. Concentrating photovoltaic thermal (CPVT) systems have emerged as promising solutions by integrating photovoltaic (PV) cells with thermal components for simultaneous electricity and heat generation. In this paper, we propose the application of the Boosted Regression Tree (BRT) algorithm to predict the entropy generation rate in a CPVT system equipped with a perforated twisted tube turbulator. Brief introduction of numerical analysis of local and global rates of frictional (S˙fr) and thermal (S˙th) irreversibilities in a CPVT system equipped with a perforated twisted tube turbulator. The results approve the efficacy of the BRT algorithm in predicting the entropy generation rate. Through comprehensive simulations and data analysis, we establish a predictive model that considers factors such as solar irradiance, fluid flow rate, tube geometry, and turbulator characteristics. The BRT model exhibits remarkable accuracy in capturing the nuanced interplay of these factors, enabling reliable estimations of entropy generation rate.

Assessment of advanced RANS models to predict the heat transfer for supercritical fluids in vertical tubes

The extreme thermophysical property changes of fluids near the pseudocritical point lead to strong buoyancy and acceleration effects, posing challenges for turbulence modelling. This paper aims to assess the performance and applicability of various turbulence models, with the intention of providing a useful reference for quickly selecting appropriate models and for models’ further improvement. Additional Favre-averaged turbulence models were implemented through user-defined scalars in ANSYS Fluent and compared to published experimental and high-fidelity simulation data. This study found that the tested turbulence models have different sensitivities to molecular Prandtl numbers, buoyancy effects, and flow acceleration. For forced convection, all turbulence models can be applied in the case of the flow acceleration number Kv<1.37×10−8, and the ZXY model has the widest application range. None of the tested turbulence models showed generalizability under mixed convective conditions. The Lien-PSA model qualitatively reproduced the wall temperature trends for all tested cases.

Modeling and experimental study condenser performance of fixed bed pyrolysis reactor: A case study of solid waste palm starch processing

Sustainable management of vermicelli waste can reduce waste in the environment. In addition, this waste can be used as a renewable fuel source. This study researched the condenser performance concerning the pyrolysis process of biomass from palm starch waste. The solid waste of palm starch was collected from the traditional industry of vermicelli noodles in Klaten District, Indonesia. The solid waste of palm starch formed into RDF-5 biomass. In this research, we use numerical and experimental methods to obtain a performance model of a pyrolysis condenser. The numerical simulation and experiment used different variations of tube models and fluid flow directions. The numerical simulation results show that the helical tube performs better than the concentric tube regarding heat transfer rate and LMTD value. After getting the numerical result, we were going to experiment with three different helical coil-type condenser pipe diameters in the Fixed bed pyrolysis reactor. Based on the experimental results, the condenser with the smallest diameter and parallel flow direction has higher liquid smoke with 41.802% yield production. The pyrolysis of palm starch waste can reduce environmental waste and turn the waste into liquid smoke. However, before it can be used as a bio-diesel additive, the liquid smoke in this research needs to be processed further.

Axial Impact Analysis of Torsion Impactor Based on Water Strike Effect

The stick-slip vibration phenomenon that occurs during the drilling process not only reduces the drilling speed, but also affects the performance of the drill pipe and the service life of the drill bit. In response to the problem of stick-slip vibration, a torsional impactor has been developed. The tool, through its internal throttle action, will produce a sudden change in the mass flow of fluid in the central tube and thus produce a water strike phenomenon, and the change in the axial force of the torsional impactor caused by the water strike effect can cope with the stick-slip vibration that occurs during drilling as well as increase the drilling efficiency. In this paper, the axial impact capacity of the tool is investigated based on its water impact effect. CFD simulations were used to determine the axial impact capacity of the torsional impactor at different drilling fluid flow rates, and the maximum equivalent force of the central tube under the water impact effect was analyzed and strength checks were performed. The research results show that: two axial vibrations occur in the center tube within half a working cycle; As the drilling fluid flow rate increased from 24L/s to 31L/s, the axial impact force of the torsion impactor increased from 32506N to 43189N; the maximum equivalent force of the center tube is 106.59 MPa, which meets the impact strength requirements. Finally, it was verified through field tests that the water impact effect generated inside the torsional impactor can effectively solve the stick-slip vibration problem and improve the rock-breaking efficiency under different drilling fluid flow rates.

Pressure drop in converging flows in three-dimensional printing of concrete

The additive manufacturing technology of extrusion of concrete mixtures through a nozzle and deposition layer-by-layer is commonly called three-dimensional concrete printing (3DCP). Such materials are rheologically characterized by yield stress and viscosity. The Bingham model is a good approximation of their rheological behavior. We have developed approximate expressions for determination of pressure for flow through slightly tapered tubes and wedge-shaped extrusion dies, starting from the Buckingham–Reiner equation for flow of a Bingham fluid in a straight tube. The predictions are compared to numerical simulations for convergence half-angles (taper) from 0° to 30° and to analytical solutions available in the literature. Good comparison has been obtained for taper angles up to 15° but the agreement deteriorates as the angle increases. Some experimental data available in the literature have been analyzed, and the challenges for prediction of pressure drop in flow of concrete mixtures through tubes and dies, including entry flow losses, are discussed.

Numerical assessment of the effect of tube geometries on the performance of phase change material (PCM) integrated solar receiver for dish-micro gas turbine systems

The temperature distribution and melting/solidification behavior of the Phase Change Material (PCM) depends largely on the arrangement of working fluid tubes in the PCM volume. A well-designed tube arrangement in the PCM results in more effective heat transfer and thermal storage. The authors previously presented a concept of Phase Change Material (PCM) integrated solar receiver for short-term thermal storage in the dish-micro gas turbine system. This solar receiver has a cylindrical shape structure filled with PCM, twelve tubes of working fluid (air) immersed in the PCM, and a conical cavity on its front surface. For such a compact thermal storage component, energy storage in the PCM and the charging/discharging rate largely depend on the arrangement of working fluid tubes in the PCM volume. The design of tubes should allow the proper distribution and release of heat in the PCM during the charging and discharging phases, respectively. In this study, the melting behavior and heat storage capacity of the PCM integrated solar receiver were analyzed by considering three different arrangements of the working fluid tubes with two cavity structures; a solar receiver with conical shaped cavity and 172° bend tubes, solar receiver with cylindrical shaped cavity and U-shaped tubes and solar receiver with conical shaped cavity with double helical tubes. The 3D numerical analysis were conducted by using Ansys Fluent 2022R1 to evaluate the effect of tube arrangements on the temperature distribution in PCM volume, melting behavior of PCM and the total storage capacity of the component. Temperature distribution on the cavity walls and heat losses were also considered. The transient simulations were performed using k−ε turbulent model with S2S radiation model and ray-tracing model. The results showed a significant effect of tube geometries on the PCM melting behavior inside the solar receiver. It was found that, in the solar receiver with conical shaped cavity and 172° bend tubes, the tubes arrangement is more suitable throughout the PCM volume and represents a more uniform temperature and melting behavior. Moreover, the pressure drop was much higher in the double helical tubes compared to other bend tubes.

Thermal energy storage with PCMs: A comprehensive study of horizontal shell and multi-tube systems with finned design

Due to its unique qualities and advantages, phase change materials (PCMs) are crucial for thermal energy storage in various applications. The poor conductivity of PCMs is known to cause delayed charging and discharging rates. So, various techniques were proposed by the researchers to improve the thermal performance of PCM systems. To address this challenge, a comprehensive numerical research was presented on a horizontally oriented finned shell-and-tube type of PCM storage. The investigation was divided into four parts: (i) effects of the quantity and arrangement of heat transfer fluid (HTF) tubes; (ii) effects of the quantity and arrangement of fins; (iii) effects of the length of fins; and (iv) effects of various configurations of the finned shell-and-tube PCM storage. The outcomes depicted that due to buoyancy impact and horizontal location, the upper portion of the PCM storage melted more quickly than the lower portion. Also, it was found that, concerning the effect of the HTF arrangement (lacking fins) on the PCM melting process, with a 67.1 % improvement factor over a base model without fins, a double vertical array of HTF tubes produced the quickest melting time. Moreover, regarding evaluating the impact of the fins arrangement (one HTF tube), with a 39 % improvement factor, the diamond arrangement of fins was shown to be the best configuration for speeding up melting. For the complete melting process (LF = 1), the most significant improvement factor of 53.2 was noted for a fin length of 5.1 mm. Finally, the obtained numerical outcomes depicted that the complete melting time (at LF = 1) was reduced by 69.14 % in the model with a double vertical array of HTF tubes and a double vertical arrangement of fins, making it the ideal layout for the finned shell-and-tube PCM storage system.

Nanofluid turbulent flow in parabolic trough collector: Insulator roof, acentric absorber tube and SiC nanoparticles effects

The key purpose of the current study is to design a parabolic trough collector (PTC) having insulator roof and an acentric absorber tube, with nanofluid using single-phase and two-phase mixture models (TPM and SPM). The effects of employing the SPM and TPM on the fluid field and heat transfer of nanofluid (SiC nanoparticles (16–90 nm) and volume fraction (0–4%) to the water and EG-water) in the absorber tube is studied. Results of present investigation shown that for both proposed (novel) and conventional PTC arrangements, the pressure drop (3%), Nusselt number (5%), friction factor (3%), energy efficiency (3%), and performance evaluation criteria (PEC) (3%) employing the TPM are greater than that of SPM. In addition, it is shown that employing the novel PTC presents greater Nusselt number (25%), energy efficiency (30%), and PEC (50%). Temperature field inside the absorber tube and heat transfer fluid zone employing the TPM are greater than that of SPM. Maximum PEC for SiC/EG-water and EG-water nanofluid are 1.67 and 1.70, respectively, for sinusoidal-wavy minichannel having a nanoparticle volume fraction of 4%, nanoparticles diameter of 90 nm, and Reynolds number of 15,001.3. Furthermore, EG-water as base fluid with a nanoparticle diameter of 90 nm presents greater energy efficiency than water.

Numerical investigation on the interaction of an oscillating bubble with the interface of a non-Newtonian fluid

The dynamics of an oscillating bubble near a liquid–liquid interface is a complex multiphase flow problem due to the highly nonlinear interaction, such as interface fragmentation and bubble tearing. When one of the liquid mediums is non-Newtonian, its constitution would significantly influence both the bubble motion and the interface evolution. In this study, a numerical model is established based on the Eulerian finite element method with the non-Newtonian fluid described by the Herschel–Bulkley model. The numerical model is validated by comparing with experimental results for a non-spherical pulsating bubble at a water–oil interface and the analytical solution for the laminar flow of non-Newtonian fluids in a circular tube. According to the simulation and analysis with different case parameters, our findings suggest that the non-Newtonian fluid forms a crater when squeezed by the bubble, and the downward jet can penetrate the bubble and further deepen the crater. As the distance parameter increases, the crater gradually disappears or even bulges. Furthermore, the yield shear stress can give non-Newtonian fluid plastic properties similar to a solid, effectively reducing the bubble's pulsation and jet load. Additionally, the flow behavior index n comes from the power-law model for non-Newtonian fluids and significantly impacts the jet's impact process. When n≤1, the crater is likelier to become funnel-shaped, whereas when n &amp;gt; 1, it is likelier to become bullet-head-shaped. In addition to enhancing the bubble's nonsphericity, the reduction in Reynolds number also weakens the crimp deformation of the interface. When the distance parameter is zero, the larger the buoyancy parameter and the less deformable the non-Newtonian fluid, the easier the bubble to split by the annular jet.

Impacts of Exponentially Growing/Decaying Pressure Gradient on Mixed Convection Flow of Viscous Reactive Fluid in a Vertical Tube: A Numerical Approach

This study examined the effects of a pressure gradient that was exponentially increasing or decreasing on the mixed convection flow of viscous reactive fluids in a vertical tube between two concentric tubes with r = 0 and r = b. The nonlinear partial differential equation governing the flow formation are solved using the implicit finite difference form where all time differentials were calculated using the forward difference formula, and second order central differences were utilized to approximate the first and second derivatives. The impacts of several physical parameters, including shear stress, the rate of heat transfer, mixed convection, viscous reactive fluid parameter, activation energy, Prandtl number, and exponential decaying/growing pressure gradient on skin friction and Nusselt number were investigated. It's intriguing to see that raising the values of Frank–Kamenetskii (λ), mixed convection (Gre) as well as exponential growing pressure term increases the velocity fluid, However, in the case of exponential decay, the parameter drop also causes the fluid's velocity to diminish. The results also showed that a small bump in the viscous reactive fluid parameter considerably improves the energy profile.

Effect of Solar Panel on Performance of Spacecraft Body-Mounted Fluid Tube Radiator

Abstract The body-mounted fluid tube radiator (BMFTR) is a highly efficient heat rejection device for spacecraft. However, the heat rejection rate of the BMFTR is negatively impacted by the presence of solar panels mounted on the exterior of the spacecraft. In this study, a heat transfer model for the BMFTR was developed, and a simulation method was created to investigate the effect of solar panels on the radiator’s performance. The accuracy of both the heat transfer model and simulation method was verified using on-orbit data from the China Tianhe module. It was found that external heat is absorbed by the solar panels, which in turn reduces the performance of the radiator. Furthermore, the decrease in the heat rejection rate was quantitatively evaluated, and it was found to be closely related to the spacecraft’s attitude and the view factor between the solar panel and the radiator. The findings of this study on the impact of solar panels on the BMFTR’s performance are meaningful for future research on spacecraft radiators and on-orbit operations.

Low-velocity impact responses of composite structures incorporating shear thickening fluid tubes under various temperatures

This study proposes a novel approach to enhance the impact resistance of carbon fiber reinforced polymer (CFRP) composite plates by incorporating an additional layer consisting of shear thickening fluid (STF)-filled tubes, resulting in a hybrid composite referred to as STF hybrid composite (STFC). The proposed STFC plates were subjected to low-velocity impact tests under varying impact energies and temperatures to consider realistic operating conditions for practical applications. It was found that the insertion of STF-filled tubes into the composite structure led to lower contact forces during impact and reduced residual velocities of the impact striker at temperatures ranging from 25 to 100 °C, thereby improving the impact resistance of the structure. Specifically, the STFC plates exhibited enhanced energy absorption capabilities, with energy absorption increasing by up to 38.10% at 25 °C under the impact energy of 2 J, potentially mitigating secondary damages within the composite structure. These results suggest that the proposed STFC hybrid composite is a promising solution for applications requiring high energy absorption capabilities.

The Efficacy of Antiseptic Treatment of Surgical Drains on Bacterial Colonisation and Surgical Site Infection Post Breast Surgery: A Systematic Review and Meta-Analysis.

Surgical site infection (SSI) is a common complicationin women with post-operative drains following breast surgery, with the risk being as high as 19%. The authors aimed to conduct the first meta-analysis to determine the efficacy of antiseptic treatment of drains to reduce the incidence of infections by comparing it to drains with no antiseptic coating. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed with an extensive search of the electronic databases retrieving 114 articles. Four articles met the inclusion criteria. The primary outcome measure was the incidence of SSIs and secondary outcome measures included the incidence of bacterial colonisation in the bulb fluid and drain tube. The incidence of SSIs was significantly lower in the antiseptic group compared to the control (CI 95% 0.09 - 0.82, p = 0.02). In addition, there was a lower incidence of colonisation from both the bulb fluid and drain tube with P values of < 0.00001 and P < 0.0001 respectively. The authors report the first meta-analysis within the literature showing the efficacy of antiseptic treatment of surgical drains on colonisation and SSIs following breast surgery. More high-quality trials are recommended to further the current evidence base.

Analysis of Flow and Pressure Drop on Tube Side of Spiral Tube Heat Exchanger under Sloshing Conditions

The utilization of the spiral tube heat exchanger (SHE) has become increasingly prevalent in large-scale liquefaction processes. However, the flow pattern and frictional pressure drop of two-phase flow in the spiral tube have been scarcely studied, particularly under offshore sloshing conditions. An experimental system had been developed to explore the flow pattern and frictional pressure drop characteristics of mixed hydrocarbon fluid in a spiral tube. Moreover, these have been developed in order to examine the effects of sloshing style (roll, pitch, heave), sloshing period (5–15 s), sloshing amplitude (5–15° or 50–150 mm), mass flux (200–800 kg/(m2·s)), vapor quality (0–1), and saturation pressure (2–4 MPa) on the frictional pressure drop of methane/ethane mixture in the spiral tube. The results indicated that sloshing conditions reduce the frictional pressure drop, thereby enhancing fluid flow. A correlation was established to predict the sloshing factor of frictional pressure drop, and the MARD under verification conditions was 6.04%. Furthermore, three flow pattern boundaries were proposed based on We* as an indicator.