Varying Flow Rates Research Articles

Interlaminar bonding assessment in vertical-oriented filament material extrusion bending specimens

Abstract Fused filament fabrication (FFF) is the leading 3D printing material extrusion process renowned for its versatility, affordability and easy production of complex components. Despite its advantages, the bonding quality between layers depends heavily on processing parameters and filament material properties. Using an orthogonal experimental design, this study investigates the effects of three nozzle-dependent variables—flow rate, temperature and speed. Poly(lactic) acid (PLA) specimens, built vertically, were evaluated via 3-point bending tests to assess flexural strength and surface roughness. The results showed that speed had an insignificant effect, while optimal performance was achieved at a 100% flow rate and 227 °C nozzle temperature across speeds of 50–70 mm/s, yielding ~ 67 MPa flexural strength and ~ 13-μm surface roughness. A reduced second-order regression model effectively captured these relationships. By focusing on bonding-related parameters, this work advances the understanding of FFF process optimization for enhanced component properties.

Comparative Analysis of BTM Systems Made of a Fireproof Composite Material with Nano Boron Nitride

The paper presents a numerical analysis of the possibilities of replacing the aluminum serpentines in the current construction of battery thermal management systems (BTMS) with cooling serpentines made of fireproof composite materials with high heat transfer parameters (fireproof epoxy resin + nano boron nitride). This approach was given by the need to replace aluminum (which, in case of fire, maintains and accelerates the combustion process) with fireproof materials that reduce/eliminate the fire risk due to improper battery operation. Numerical analysis methods were used through simulation to identify the most efficient design among the single-channel, multichannel, multiflow and multiple coolant inlet–outlet solutions for cooling serpentine. In addition to these geometric constructive parameters, the variation of the coolant flow rate (9, 12, 15 and 18 L/min) and coolant inlet temperature (17, 20 and 25 °C) was also considered. The obtained results showed that the single-inlet nanocomposite resin cooling serpentine four-channel configuration presents the highest cooling efficiency of the cells that form the battery module while ensuring very good thermal uniformity as well. These findings are supported by the lowest average heat absorption by the batteries, of 34.44 kJ, as well as the lowest average internal resistance difference (caused by thermal gradients), of 5.23%. Future research is needed to identify the degree of structural resistance of serpentines made of fireproof composite material to external stresses (vibrations characteristic of the operation of electric vehicles).

Catalytic Cu2O/Cu Site Trades off the Coupling and Etching Reactions of Carbon Intermediates for CO2-Assisted Graphene Synthesis.

In the chemical vapor deposition (CVD) synthesis of graphene, the surficial chemical state of the metal substrate has exerted key roles in all elemental reaction steps determining the growth mechanism of graphene. Herein, a CO2-participated annealing procedure is designed to construct catalytic Cu2O/Cu sites on Cu foil for the graphene CVD synthesis with CO2/CH4 as carbon sources. These Cu2O/Cu species can catalyze the CH4 decomposition and subsequent C─C coupling to form C2 intermediates for fast growth of monolayer hexagonal graphene domains with a diameter of ≈30µm within 0.5min. The graphene growth kinetics can be bidirectionally regulated merely with the variation of CO2 flow rate during annealing and growth stages, in association with the Cu+/Cu0 ratio, enabling simultaneous control over the size and shape of graphene domains. Density functional theory (DFT) calculations indicate that the catalytic Cu2O/Cu sites reduce the activation energy by ≈0.13eV for the first dehydrogenation of CH4, allowing the growing rate of graphene driven by coupling of C2 intermediates faster than their etching rate by O-containing *O and *OH species. The work provides novel insights into heterostructured nano-catalyst consisting of zero valent metal and variably valent metal oxide that facilitate the controllable synthesis of graphene materials.

Experimental measurements of particle deposition in the human nasal airway.

Intranasal drug delivery is a promising non-invasive method for administering both local and systemic medications. While previous studies have extensively investigated the effects of particle size, airflow dynamics, and deposition locations on deposition efficiency, they have not focused on the thickness of deposited particles, which can significantly affect drug dissolution, absorption and therapeutic efficacy. This study investigates the deposition patterns of dry powder particles within the nasal airway, specifically examining how factors such as flow rates, particle size, and particle cohesiveness influence deposition patterns and their thickness. Using optical coherence tomography (OCT), this study assessed the deposition behaviour of three different lactose powders in a reconstructed nasal airway model at three key anatomical locations under varying flow rates (15, 35 and 55 L/min). Computational fluid dynamics (CFD) simulations were conducted to complement the experimental data, demonstrating the airflow dynamics in the nasal airway and highlighting recirculation zones that impact deposition patterns. The results revealed that the anterior section of the nasal airway is particularly effective at capturing particles, with localised flow patterns playing a critical role in particle accumulation. These flow patterns, combined with particle size and cohesiveness, are key factors in determining where and how particles cluster, leading to thicker deposition in specific areas of the nasal airway. This study addresses the gap in understanding how these factors influence deposition thickness and spatial distribution, ultimately contributing to the optimisation of nasal drug delivery systems.

Lattice-Strain Engineering of High-Entropy-Oxide Nanoparticles: Regulation by Flame Spray Pyrolysis with Ultrafast Quenching.

The lattice-strain engineering of high-entropy-oxide nanoparticles (HEO-NPs) is considered an effective strategy for achieving outstanding performance in various applications. However, lattice-strain engineering independent of the composition variation still confronts significant challenges, with existing modulation techniques difficult to achieve mass production. Herein, a novel continuous-flow synthesis strategy by flame spray pyrolysis (FSP) is proposed, which air varying flow rates is introduced for fast quenching to alter the cooling rate and control the lattice strain of HEO-NPs. Experimental results demonstrate that as the flow rate of air increases from 0 L to 24 L min-1, the cooling rate has increased by more than ten times, and the tensile strain of the HEO-NPs increases by 2.75%. Utilizing the oxygen evolution reaction (OER) activity as an indicator, it is observed that the overpotential to achieve a current density of 10mA cm-2 is reduced by 25mV. Importantly, this approach enables the simple and efficient regulation of lattice strain in HEO-NPs (110 mg min-1). Thus, this study provides a new approach for both the mass production and regulation of lattice strain in HEO-NPs.

Flow environment affects nutrient transport in soft plant roots.

This work estimates Michaelis-Menten kinetics parameters for nutrient transport under varying flow rates in the soft roots of Indian mustard (Brassica juncea) using a plant fluidic device. To find the metallic components within the roots, inductively coupled plasma mass spectrometry (ICP-MS) analysis was performed. The flow rate-dependent metabolic changes were examined using Raman spectral analysis. In addition, three-dimensional numerical simulations were conducted to assess mechanical stresses resulting from the concentration difference that enhances osmotic pressure and flow loading at the root-liquid interface. Convection, the primary mode of nutrient transport in flowing media, was observed to reduce nutrient uptake at higher flow rates. In contrast, diffusion became more prevalent in areas where the complex root structure restricted the flow field. The concentration gradient between the upstream and downstream regions of the root caused nutrient diffusion from downstream to upstream. As seen, an increase in flow rate resulted in a decrease in root length due to the reduction of advantageous metabolites, which led to lower average mechanical stress and osmotic pressure loading. Additionally, osmotic pressure at the root-liquid interface was found to increase over time. Numerical simulations revealed that the average internal mechanical stress was substantially greater when osmotic pressure was considered. This emphasizes the importance of accounting for osmotic pressure when assessing mechanical stress in roots. This study uses a fluidic device that replicates hydroponic conditions for the first time in order to evaluate the convection-dependent Michaelis-Menten kinetics of nutrient uptake in plant roots.

Particle Vertical Mixing and Horizontal Conveyance Within an Ambient Temperature Fluidized Bed

Previous studies have shown the advantages of particle-to-sCO2 fluidized bed (FB) heat exchangers, which include high heat transfer coefficients, low material cost, and the ability to horizontally convey solid particles. This paper outlines the design and testing of a compact cold flow FB test apparatus to characterize horizontal conveyance through convolutions within a 100 kWth FB heat exchanger design. Horizontal conveyance is an advantage in FBs because it enables more compact designs for heat exchangers. Two mass flow rates, 0.5 & 1 kg/s, at the inlet & outlet of the FB. To determine consistency of the flow rates, Student’s t-tests were used to assess whether the inlet & outlet values were statistically similar. The mass flow rate exiting the bed was statistically similar to the flow rate entering the bed for both cases, but each case featured a wider range and standard deviation. The range and standard deviation of the 1 kg/s flow rate was 0.69-1.23 kg/s and 0.12 kg/s respectively, and the 0.5 kg/s test featured a range and standard deviation of 0.37-0.73 kg/s and 0.09 kg/s, respectively. These measurements provide confidence that large-scale designs can successfully horizontally convey particles at ````~1.5x minimum fluidization velocity (U­mf) without significant variation in flow rate. A method to characterize the degree of particle vertical mixing and bubble frequency within the FB is also introduced. By using a high-resolution camera together with particle velocimetry, particle motion in the X and Y directions can be estimated to assess bed mixing and bubble frequency.

Study of Rewetting Behavior in AHWR Fuel Cluster During Loss of Coolant with Water Jet Impingement

This study investigates the rewetting behavior of an Advanced Heavy Water Reactor (AHWR) fuel rod bundle during a loss-of-coolant accident using computational fluid dynamics simulations with ANSYS CFX. The analysis focuses on the cooling effectiveness of radial jet impingement at varying flow rates and its impact on rewetting temperature and wetting delay. Simulations were conducted by maintaining a constant initial wall temperature, with cooling curves and contour profiles extracted from various angular positions along the axial rod surfaces. The results reveal that rewetting is faster near the jet sections due to enhanced coolant interaction, while areas farther from the jets exhibit delayed wetting and elevated wall temperatures, where vapor accumulation hinders heat dissipation. Higher flow rates minimize wetting delays and improve cooling by promoting transition and nucleate boiling. However, irregular coolant splashing and vapor dominance disrupt the uniformity of rewetting across the bundle. The study highlights the limited impact of increased flow rates on achieving consistent rewetting along the entire rod length, with substantial fluctuations observed in cooling performance at different vertical positions. The findings emphasize the need for further research under high-temperature steam conditions to better understand boiling mechanisms and improve the stability of emergency cooling systems in nuclear reactors.

Optimal Design and Operation of an Ultrasonic Driving System for Algae Removal Considering Underwater Environment Load.

This study investigates the optimal design and operation of an underwater ultrasonic system for algae removal, focusing on the electromechanical load of Langevin-type piezoelectric transducers. These piezoelectric transducers, which operate in underwater environments, exhibit variations in electrical-mechanical impedance due to practical environmental factors, such as waterproof molding structures or variations in pressure and flow rates depending on the water depth. To address these challenges, we modeled the underwater load conditions using the finite element method and analyzed the impedance characteristics of the piezoelectric transducer under realistic environmental conditions. Based on this analysis, we developed an ultrasound-driven system capable of efficient output control by incorporating the impedance characteristics of the transducer under load variations and subaquatic conditions. This study proposes analytical and experimental methods for modeling and analyzing practical ultrasound-driven systems for algae removal.

The Effect of Corrosion Inhibitors on the Corrosion Behavior of Ductile Cast Iron

Based on actual service environment parameters, this experiment investigated the change in the corrosion rate of nodular cast iron (DCI) in an environment containing organic (triethanolamine phosphate, PTEA) and inorganic (hexametaphosphate, SHMP) inhibitors, and analyzed the effects of both inhibitors and the pH value of the solution on the corrosion behavior of DCI. Additionally, a variable flow rate device was used to conduct immersion tests, enabling the accurate evaluation of the materials’ corrosion resistance in an actual service environment. After a certain period, the corrosion of the DCI surface was observed, and the weight loss corrosion rate of the materials was calculated to analyze the differences in corrosion resistance under varying environmental parameters. It was found that the inhibitory effect of both inhibitors on DCI increased with the immersion time, and the inhibitory effect of the SHMP inhibitor was more pronounced under alkaline conditions. Based on the electrochemical and flow rate immersion test results, it can be concluded that, in the solution environment used in this experiment, the inhibitory effect of the SHMP inhibitor on DCI is stronger than that of the PTEA inhibitor.

Luminal flow in the connecting tubule induces afferent arteriole vasodilation.

Renal autoregulatory mechanisms modulate renal blood flow. Connecting tubule glomerular feedback (CNTGF) is a vasodilator mechanism in the connecting tubule (CNT), triggered paracrinally when high sodium levels are detected via the epithelial sodium channel (ENaC). The primary activation factor of CNTGF-whether NaCl concentration, independent luminal flow, or the combined total sodium delivery-is still unclear. We hypothesized that increasing luminal flow in the CNT induces CNTGF via O2- generation and ENaC activation. Rabbit afferent arterioles (Af-Arts) with adjacent CNTs were microperfused ex-vivo with variable flow rates and sodium concentrations ranging from < 1 to 80mM and from 5 to 40 nL/min flow rates. Perfusion of the CNT with 5mM NaCl and increasing flow rates from 5 to 10, 20, and 40 nL/min caused a flow-rate-dependent dilation of the Af-Art (P < 0.001). Adding the ENaC blocker benzamil inhibited flow-induced Af-Art dilation, indicating a CNTGF response. In contrast, perfusion of the CNT with < 1mM NaCl did not result in flow-induced CNTGF vasodilation (P > 0.05). Multiple linear regression modeling (R2 = 0.51; P < 0.001) demonstrated that tubular flow (β = 0.163 ± 0.04; P < 0.001) and sodium concentration (β = 0.14 ± 0.03; P < 0.001) are independent variables that induce afferent arteriole vasodilation. Tempol reduced flow-induced CNTGF, and L-NAME did not influence this effect. Increased luminal flow in the CNT induces CNTGF activation via ENaC, partially due to flow-stimulated O2- production and independent of nitric oxide synthase (NOS) activity.

Research on Water Flow Control Strategy for PEM Electrolyzer Considering the Anode Bubble Effect

At higher current densities, the bubble effect in the anode flow field of the PEM electrolyzer (PEM EL) worsens mass transfer losses and energy consumption. This study employs a moderate increase in the water flow rate to remove accumulated bubbles under fluctuating electrical input, thereby improving PEM EL system efficiency. An enhanced PEM EL equivalent circuit model incorporating bubble over-potential based on the oxygen volume fraction is developed. Considering the energy consumption of auxiliary equipment and the reduction in losses from mitigating the bubble effect, a numerical simulation evaluates the impact of flow rate variations on overall electrolysis energy consumption, leading to a comprehensive energy consumption model for the PEM EL system, incorporating electrical, chemical, and thermal energy conversions. The control objective is to maximize system efficiency by optimizing the water flow rate, with a performance-preset-based controller implemented in MATLAB/Simulink. The simulation results show that the controller can accurately track the target flow rate, and the dynamic regulation time improved by 1.5 s compared to the traditional performance constraint function, better matching the rate of change in electrical energy. Under the water flow control mode, hydrogen production increased by 6.6 L within 130 s of the simulation, available energy increased by 8.32 × 106 J, and the efficiency of the PEM EL system improved by 2.79%.

In Vitro Analysis of Pressure Resistance in the Paul Glaucoma Implant and Ahmed ClearPath 250 With and Without Polypropylene Thread Inside the Tube.

Pressure resistance characteristics of the Paul glaucoma implant (PGI) and Ahmed ClearPath 250 (ACP), with and without the insertion of polypropylene thread in their tubes, were evaluated. The in vitro flow pressure was evaluated at varying flow rates, both with and without threads (6-0 for PGI and 4-0 or 3-0 for ACP). Cross-sectional areas of the tube lumen and thread were measured to calculate pressure resistance using the Hagen-Poiseuille equation. For the PGI without the thread, the pressure remained relatively low and constant across all flow rates. In contrast, with the insertion of a 6-0 thread, there was a significant increase in pressure resistance, with the pressure increasing from 7.5mmHg at 1 µL/min to 43.8 mmHg at 5 µL/min. For the ACP, the pressure resistance remained relatively constant across all flow rates without a thread and with either 4-0 or 3-0 threads. However, the pressure was higher with 3-0 threads compared with a 4-0 thread. The actual measured pressures agreed well with theoretical values in the no-thread conditions, but were consistently higher than the theoretical values in the threaded conditions. Inserting polypropylene threads into the tubes of nonvalved glaucoma drainage devices significantly affects pressure resistance with various degree. PGI with a 6-0 polypropylene thread may not require external tube ligation to prevent hypotony, whereas ACP with a 4-0 thread likely requires additional ligation. Using a 3-0 thread in ACP may enhance pressure resistance sufficiently to avoid tube ligation, but this requires careful clinical consideration.

Rapid microfluidic perfusion system enables controlling dynamics of intracellular pH regulated by Na+/H+ exchanger NHE1.

pH regulation of eukaryotic cells is of crucial importance and influences different mechanisms including chemical kinetics, buffer effects, metabolic activity, membrane transport and cell shape parameters. In this study, we develop a microfluidic system to rapidly and precisely control a continuous flow of ionic chemical species to acutely challenge the intracellular pH regulation mechanisms and confront predictive models. We monitor the intracellular pH dynamics in real-time using pH-sensitive fluorescence imaging and establish a robust mathematical tool to translate the fluorescence signals to pH values. By varying flow rate across the cells and duration for the rinsing process, we manage to tweak the dynamics of intracellular pH from a smooth recovery to either an overshooting state, where the pH goes excitedly to a maximum value before decreasing to a plateau, or an undershooting state, where the pH is unable to recover to ∼7. We believe our findings will provide more insight into intracellular regulatory mechanisms and promote the possibility of exploring cellular behavior in the presence of strong gradients or fast changes in homogeneous conditions.

Droplet Size Distributions from PWM-Controlled Hollow-Cone Nozzles Operated at High Modulation Frequencies and Pressures

HighlightsPWM valves were investigated to control nozzles at modulation frequencies up to 40 Hz with pressures up to 2068 kPa.Modulation frequency did not affect droplet size distributions and uniformity of hollow cone nozzles.Duty cycles between 30% and 100% produced stable droplet size distributions from variable flowrate nozzles.Matching PWM valve speeds to detection sensor speeds could further increase precision application efficiency.Abstract.Sprayers equipped with pulse width modulated (PWM) solenoid valves and the most accurate laser-scanning sensors allow real-time variable rate applications of pesticides based on canopy volumes. However, the accuracy of variable-rate applications could be increased by accommodating the flow modulation speed of the PWM valves to match the high speeds of the sensor detecting crop architectures. Based on previous investigations of 12 commercially available high-frequency PWM valves, two PWM valves with the highest modulation capability were selected for further evaluations. These investigations included the influence of modulation frequencies and duty cycles on the droplet size distribution and uniformity of two disc-core hollow-cone nozzles manipulated with the two PWM valves operated at pressures of 1034, 1380, and 2068 kPa. The modulation frequencies ranged from 10 to 40 Hz and duty cycles (DUCs) were between 10% and 100%. Test results showed that droplet size distribution and uniformity remained consistent with varied modulation frequencies. However, DUCs slightly affected droplet size distribution and uniformity, especially when DUCs were 30% and below. Therefore, there would be a potential to integrate these high-frequency PWM valves, properly operated at DUCs in the range between 30% and 100%, into orchard sprayers to further increase the variable-rate application accuracy while maintaining stable droplet size distributions. Keywords: Orchard sprayer, Pesticide, Precision farming, Pulse width modulation, Specialty crops, Variable rate application.

Scaled asymptotic solution nets for unlabeled seepage equation solutions with variable well flow

The seepage equation is essential for understanding fluid flow in porous media, crucial for analyzing fluid behavior in various pore structures and supporting reservoir engineering. However, solving this equation under complex conditions, such as variable well flow rates, poses significant challenges. Although physics-informed neural networks have been effective in addressing partial differential equations, they often struggle with the complexities of such physical phenomena. This paper presents an improved method using physical asymptotic solution nets combined with scaling before activation (SBA) and gradient constraints to solve the seepage equation in porous media under varying well flow rates without labeled data. The model consists of two neural networks: one that approximates the asymptotic solution of the seepage equation and another that corrects approximation errors to ensure both mathematical and physical accuracy. When the well flow rate changes, the network may fail to fully satisfy the asymptotic solution due to pressure distribution variations, resulting in sub-optimal outcomes. To address this, we incorporate gradient information into the loss function to reinforce physical constraints and utilize the SBA method to enhance the approximation. This gradient information is derived from the pressure distribution at the previous flow rate, and the SBA method regulates weight adjustments through an adjustment coefficient constrained by the loss function, preventing sub-optimal local minima during optimization. Experimental results show that our method achieves an accuracy range of 10−4 to 10−2.

Experimental study on the performance of Peltier TEC12706 as a cooling and heating media

The application of refrigeration spans a wide range of industries, from household needs to the oil and gas sector, employing various cooling methods. One rapidly developing approach is the use of Peltier devices, particularly the TEC1 12706 model, due to its compact size and widespread availability. It is essential for students to understand the application of Peltier technology, which necessitates the creation of practical tools for both educational and research purposes. Most existing research on Peltier devices focuses on air conditioning systems with fixed loads; therefore, it is imperative to explore their cooling and heating effects in dynamic environments. To address this gap, this study investigates the performance of Peltier modules as cooling and heating systems for moving media. A prototype of a cooling and heating module (heat pump) was developed using Peltier devices, and its performance was evaluated by varying the flow rates of hot and cold water (1.62/1.02; 1.2/0.8; and 0.9/0.68 L/min) and the number of operational Peltier elements (2, 4, 6). Calculations using the relevant formulas yielded the Coefficients of Performance (COP): COPc = 0.45, COPh = 1.37, and COPtot = 1.82. The results revealed that the cooling performance coefficient is lower than both the heating and total performance coefficients. Additionally, variations in flow rates and the number of installed Peltier devices showed minimal impact on cooling and heating performance coefficients.

Slurry Transportation Characteristics of Potash Mine Cemented Paste Backfills via Loop Test Processing

This study evaluated the properties and processing of cemented paste backfills (CPBs) for potash mining through loop tests. The CPBs were made with steel slags as the binder, granulated potash tailings as the aggregate, and waste brine water as the liquid phase. The effects of solid concentration and steel slag dosage on the transport and mechanical properties of CPBs were assessed. The loop test demonstrated that all CPB slurries performed well, exhibiting strong long-distance pipeline transport capabilities. The 28-day compressive strength of the backfills exceeded 1 MPa, meeting the design requirements for backfill strength. The key rheological parameters, including yield stress (τ0) and viscosity coefficient (η), were comprehensively and theoretically analyzed based on the variations in pressure loss per unit distance of the filling slurry measured during the loop test. The empirical formulas for CPB pressure loss, accounting for varying flow rates and pipeline diameters, were derived with an error margin under 2%. The response surface analysis showed that the affecting extents of factors on pressure loss in CPB slurry were ranked as follows: solid concentration &gt; cementing agent content &gt; flow rate. This study offered valuable guidance for the processing of potash mine backfill operations.

Thermoeconomic analysis in solar collector fields: a focus on constant flowrate and variable flowrate models

In this study, the operation models with constant flowrate and variable flowrate of a flat-plate solar collector field are analysed. The model that achieves greater energy utilization and lower operating costs was determined under two conditions: when scaling fouling occurs in the collector tubes and when a clean operation (without fouling) is considered. The case study involves a pasteurization plant operating at temperatures above 85°C. The operational scenarios are as follows: 1) Variable flowrate: the flowrate is adjusted based on environmental conditions to maintain a constant outlet temperature, and 2) Constant flowrate: the flowrate remains constant, resulting in varying collector outlet temperatures depending on weather conditions. The results show that under clean conditions, operating with variable flowrate yields a lower cost per kWh of captured energy ($0.048/kWh). In the presence of fouling, the cost of operating with variable flowrate significantly increases to $0.15/kWh, while constant flowrate results in the lowest cost ($0.077/kWh).

Operational features of collecting pipelines in the presence of transit and groundwater level slope

The conditions of operation for pressure collecting drainage pipelines in melioration systems that function in the presence of transit flow and groundwater surface levels have been considered. The system of differential equations describing the fluid motion with variable flow rate in the drainage pipe has been analyzed, taking into account the inflow of liquid from the surrounding soil through the side walls in a filtration mode. This system of equations consists of the hydraulic equation of variable mass and a modified filtration equation. The pipeline under study is laid horizontally and operates with a groundwater level slope. A significant complication in the operation of such pipes is the presence of transit flow that enters their initial cross-section and is transported along the entire length of the drainage pipeline. By introducing new variables, the original system is transformed into a dimensionless form. The solution to this system of equations is presented. It is shown that, in this case, the solution to the original system of equations depends on the magnitude of four main factors: the resistance coefficient of the collection drainage pipeline «ζl»; the generalized parameter «A» which comprehensively considers the structural and filtration characteristics of the flow under consideration; the slope of the groundwater level «I»; and the magnitude of the transit flow «Qtr» The analysis employs the concept of an infinitely long horizontal drainage pipeline that operates with a groundwater level slope and transit flow, or, equivalently, a pipeline with infinite filtration capacity of the side wall surfaces. Based on the conducted analysis, relatively simple and convenient analytical expressions have been obtained for calculating the variation of flow rate and head loss along the length of the drainage pipeline operating with transit flow. To simplify the calculations, corresponding auxiliary graphical dependencies have been proposed.