Mixture Flow Research Articles

Performance evaluation of pigmented fair-faced concrete under various environments: Mechanical properties, apparent properties, and color stability

Fair-faced concrete is green concrete that is directly decorated by its texture. For a more stunning visual impact, pigmented fair-faced concrete with more colors on the surface is prepared. However, the effects of different pigments and service environments on pigmented fair-faced concrete need to be explored. Therefore, four iron oxide inorganic pigments were employed to prepare pigmented fair-faced concrete, and the changes in its fresh properties and mechanical properties were studied through slump, slump flow, and compressive strength tests. Meanwhile, camera analysis and colorimetry were utilized to evaluate the changes in its apparent properties and color stability under four different distinct service environments in this experiment. Results indicate that incorporating pigments reduces both the slump and slump flow of the fresh mixture, and its fresh properties gradually decrease as the pigment content increases. The slump and slump flow of concrete with 6 % iron oxide yellow (IOY) were 30.00 % and 44.00 % lower than the control. Adding IOY and iron oxide red (IOR) can improve the 7-d and 28-d compressive strength of concretes. The 28-d compressive strength of concrete with 2 %-6 % IOY increased by 7.72 %, 11.78 % and 15.09 % over the control. Meanwhile, the surface pore area of concrete with IOY is the lowest and that of concrete containing 2 % IOY is 3.97 cm2/m2. Additionally, the color stability of concrete performs best in water immersion environments and worst in natural environments. It is noteworthy that the concrete added with IOY exhibits excellent color stability under all four service environments. This study aims to evaluate the effects of different pigments on concrete properties and investigate the color stability of four types of concrete under diverse service conditions. The findings will promote the application of pigmented fair-faced concrete in construction and provide technical insights for future research.

The Effect of Ellipsoidal Particle Surface Roughness on Drag and Heat Transfer Coefficients Using Particle-Resolved Direct Numerical Simulation

The purpose of this study is to estimate the effect of roughness layer thickness on the heat transfer and drag coefficients of ellipsoidal particles. Using an OpenFOAM-based particle-resolved direct numerical simulation (PR-DNS) method, we calculated the drag coefficient and Nusselt number for an isolated axisymmetric nonspherical particle with a rough surface in a uniform flow. The PR-DNS results indicate that the drag coefficient varies linearly with the effective roughness Sef at different angles, which can be expressed as CD=kSef−1+CD0. The changes in k are consistent with the Happel and Brenner equation. Furthermore, the influence of roughness on the heat transfer efficiency factor can be represented by Ef=Sef−65. The models for the drag coefficient and Nusselt number are valid within the ranges 1.25≤Ar≤2.5,1≤Sef≤2, and 10≤Rep≤200, thereby extending the applicability of the equations developed for smooth particles. These newly developed correlations for the drag coefficient and Nusselt number can be utilized for non-isothermal flows of particle mixtures containing materials with various rough-surfaced ellipsoids.

Adsorption-absorption technique for effective CO2 capture

ABSTRACT This paper presents a study on the removal of CO2 gas from gas mixture (CO2/N2) of 14% CO2 using adsorption onto zeolite 13X in a fluidized bed at 298 K and 1 atm pressure. The effects of static bed height (5–25 cm) and rate of flow of the gas mixture (6–14 L/min) on the breakthrough time were studied. The desorption of CO2 was performed by absorbing the adsorbed CO2 molecules using NaOH solution (0.1 M). The absorption process which was accompanied with chemical reaction achieved two objectives. The first was converting CO2 gas into a valuable substance (Na2CO3) which could be used in many industries. The second was the storage of CO2 gas in what was called a chemical carrier which could emit the gas when it was needed. The effect of static bed height (5–25 cm) on the absorption process in the fluidized bed was also studied. For the adsorption process, the results showed that the breakthrough time increased with decreasing the flow rate but with increasing the static bed height. In the desorption process, the total amount of absorbed CO2 molecules was 396 mg, achieving a recovery of 90.8% at 5 cm static bed height.

Equivalence Ratio-Driven Flame Response of an Industrial Premixed Burner: Experiments and Modeling

Abstract This paper presents an analysis of the unsteady heat release rate response of premixed flames to equivalence ratio perturbations for an industrial premixed swirl-based burner. During this investigation, perfectly and technically premixed flames were acoustically forced via fuel/air mixture flow and air flow modulations, respectively, at the same operating conditions. From the resulting flame transfer functions (FTFs), measured using the multimicrophone method, the equivalence ratio driven FTF was isolated and extracted by removing the velocity driven component, i.e., the measured FTF from the perfectly premixed flame, from the technically premixed FTF with two novel extraction techniques. The results are compared with FTFs obtained directly in a previous experimental campaign where the fuel flow was acoustically forced, the resulting equivalence ratio fluctuations measured via an infrared absorption technique, and the heat release rate response to the forcing was quantified using chemiluminescence measurements. The results from both measurement approaches agreed well highlighting the validity of the techniques. Further, to understand the governing features of the equivalence ratio driven FTF, a physics-based analytical model following the G-equation approach was developed. The contributions from flame surface area, flame speed, and heat of reaction oscillations were modeled to describe the heat release rate dynamics. A limited number of physical parameters in the analytical model were anchored on one test condition, optimized and restricted to values, which were all physically reasonable, and were subsequently used for model predictions at other operating conditions. The FTF model predictions compared well with experimental data across a range of different operating conditions. Finally, the relative contributions from flame surface area, flame speed, and heat of reaction oscillations on the features of the FTFs were identified and explored.

Mass transfer in developing flow of a reactive mixture through a curved cylindrical tube

Mass transfer in developing flow of a reactive mixture through a curved cylindrical tube

Numerical simulation of flame propagation characteristics of NH3/Air flames assisted by non-equilibrium plasma discharge

Nanosecond non-equilibrium plasma-assisted combustion technology emerges as a reliable novel approach to enhance the flame propagation speed of NH3. In this study, we developed a zero-dimensional + one-dimensional (0-D+1-D) non-equilibrium plasma-assisted combustion model to investigate the impact of nanosecond pulse discharge on the freely propagating flame speed of NH3/Air mixture. The results reveal that due to the plasma discharge, abundant intermediate species (N2H4, N2H3, NO, H2O2) are formed at the inlet and are subsequently transported downstream, facilitating flame propagation. As a result, the speed of the 1-D freely propagating flame increases, and the flame front is closer to the inlet compared to the non-plasma condition. The transport effect of H2 is also evident, with high concentrations of H2 from the inlet providing the basis for reactions at the flame front that promote combustion. Furthermore, after the initial mixture flows into the flame front, a slight increase in heat release is observed, but this increase occurs within a very limited distance. Notably, in the case of plasma, a stronger heat release is evident at the flame front. Moreover, with plasma, the peaks of OH, H, O, NH2, and HO2 are higher and earlier than those of the non-plasma case due to the transport and kinetic effects of plasma. Pathway flux analyses reflect significant changes in the production and consumption paths of the three components OH, H, and O, which are most important for consuming NH3 due to plasma addition. The higher OH mass fraction promotes the chain reactions that consume NH3, effectively enhancing the flame propagation speed. Novelty and significance statementThis study introduces a novel 0-D+1-D nanosecond non-equilibrium plasma-assisted combustion model to examine the impact of nanosecond pulse discharge on NH3/Air flame propagation. It uniquely analyzes the interaction between species at the inlet and flame front, highlighting the transport effects of plasma-generated intermediates (N2H4, N2H3, NO, H2O2, H2) that enhance flame speed, with a detailed pathway analysis of key species (O, OH, H).

CFD Modeling of Film Condensation from a Steam-Air Mixture in Vertical Channels

Steam condensation in the presence of a noncondensable gas is of vital importance for passive cooling containment systems. The noncondensable gas causes a significant reduction in the condensation rate and heat transfer across the containment, which is important for postulated loss-of-coolant accidents in a nuclear reactor. In this work, computational fluid dynamics models of condensation and the adjacent single-phase steam-air mixture flow are developed for laminar and turbulent flow in vertical channels by two distinct wall condensation modeling approaches using the commercial code STAR-CCM+. The first is the fluid film model available in STAR-CCM+, which solves liquid layer governing equations with connections to the adjacent gas mixture flow. The second is a user-defined wall condensation model that neglects the fluid film and instead accounts for mass, momentum, and heat transfer via user-defined volumetric sink terms adjacent to the cold wall. The condensation models are assessed by first comparing the calculated results with the numerical solution of laminar flow, solved using a complete two-phase model that solves parabolic equations based on conservation of mass, momentum, energy, and species for each phase. Next, the results of a two-dimensional analysis are compared with COPAIN experiments and existing numerical solutions from three-dimensional analyses. The comparisons include new, detailed results that have not been reported in previous analyses of a COPAIN case. These new results include local field profiles of velocity, temperature, and air mass fraction, and local mass flux.

Development and testing of a measuring chamber for a device for express analysis of milk quality in a flow

Mechanization and robotization of dairy farms require the development of technologies for assessing the quality of manufactured products. Monitoring milk composition and milking duration in real time is especially important for prompt response to deviations in animal physiological state parameters and timely adjustment of rations when milk yields decrease. The first version of the scatterometric device for express analysis of milk quality used a glass measuring chamber with a simple round cross-section, but it did not ensure the reduction of the turbulent flow of the milk-air mixture to laminar. This study presents the development and testing of a prototype of a measuring chamber that provides deceleration and laminarization of the milk-air mixture flow. The device operates at a milking capacity of 1 to 6 l/min, flow speed from 0.2 to 1.8 m/s. In the developed measuring chamber, a special bypass is created at an angle of 45° so that it has a common slot with the main tube. In this bypass, the flow of the milk-air mixture is slowed down to reduce turbulence and the number of air bubbles that interfere with the operation of scatterometric devices. The measurement area of the device is located in the upper part of the bypass. As a result, the developed measuring chamber has an internal diameter of the main part of 15 mm, the bypass of 11 mm, and provides close to 100% filling of the branch with liquid at the moment of the milk plug passage. The developed measuring chamber allowed the new version of the express milk quality analysis device to achieve increased accuracy and stability of measurements.

Convection flow of NE-phase change material-water mixture in evacuated tube solar collector manifold: Numerical analysis of MHD double-diffusive convection and exothermic reaction

This study investigates the convection flow of nano-encapsulated phase change material (NEPCM)-water mixture in an evacuated tube solar collector manifold, focusing on the effects of magnetohydrodynamic (MHD) double-diffusive convection and exothermic reaction. Computational fluid dynamics simulations using the Galerkin finite element method were employed to analyze temperature and concentration distributions, fluid flow, melting zone of PCM nanocapsules, Nusselt number, Sherwood number, entropy generation, and thermal performance. The numerical analysis considers a range of dimensionless parameters, including Rayleigh number (Ra=103−105), Lewis number (Le=0.1−10), buoyancy ratio (Nz=1−5), nanoparticle concentration (ϕ=0.01−0.035), fusion temperature (ϴf=0.1−0.9), Stefan number (Ste=0.1−0.9), Hartmann number (Ha=0−50), magnetic field inclination angle (γ=0°−90°), and Frank-Kamenetskii number (FK=0−2.5). Results show that increasing Ra enhances the average Nusselt number (Nuav) by up to 156.1 % and the average Sherwood number (Shav) by up to 104.5 %, while increasing the total entropy generation by up to 13,155 %. Increasing FK reduces Nuav by up to 42.2 % but increases Shav by up to 13.1 %. The Lewis number and buoyancy ratio significantly influence the hydrothermal performance, with Nuav exhibiting non-monotonic behavior and Shav increasing by up to 240.9 % as Le increases. The nanoparticle concentration enhances Nuav by up to 49.7 %. Interestingly, the magnetic field effects are less pronounced than in previous studies, with Ha having a minor impact on Nuav and Shav. These findings have significant implications for the design and optimization of evacuated tube solar collectors and other thermal energy storage systems, potentially leading to improved efficiency and performance in real-world applications.

An Effective Method for Reproducing the Flow of a Gas-Liquid Mixture Using a Flow Standard

The appearance on the market of measuring equipment of multiphase flowmeters used in the oil and gas industry to measure the amount of extracted hydrocarbons directly at wells without preliminary separation and performing the function of operational accounting raised the question of their metrological support in accordance with the requirements of regulatory documents of the sphere of state regulation in this field of measurements. His decision was to create a reference base, the basis of which was the State primary special standard for units of mass flow of gas-liquid mixtures GET 195-2011 and a verification scheme for measuring multiphase flow rates, regulated by GOST 8.637-2013. When transmitting units of volume and mass flow of a multiphase mixture with the required accuracy, the main problem is the difficulty of reproducing and maintaining stability of several flow parameters at once – mass flow and content of liquid components (water and oil simulator) and volume flow of the gas phase. It should also be borne in mind that test programs for the purpose of approving the type of multiphase flow measuring instruments, as well as verification and calibration methods, provide for changing the modes of reproduction of a gas-liquid mixture, covering the measurement ranges of multiphase flowmeters. Such standards used in practice represent a very complex measuring system consisting of storage tanks for components, supply pumping and compressor units, control equipment, mixers and separators, measuring instruments for the physical parameters of multiphase flow components and an automated control system. Given the high cost of multiphase standards, when creating them, effective methods and methods should be used to reproduce the flow of a multiphase mixture with specified parameters, as well as to make a fairly rapid transition to the next mode provided by the program or methodology, which will reduce the time and production costs for the procedure of transferring units of measurement from the standard to the working measuring instrument. This article describes a method for reproducing the flow rate of a gas-liquid mixture according to the original technological scheme introduced during the development of the 1st category standard. Constructive solutions are presented that increase the efficiency of the liquid component separation apparatus to increase the dosing accuracy, as well as expand the range of reproduction of the flow rate and parameters of the multiphase flow, ensuring the consistency of the composition of the liquid mixture at a given regime. An original rational method of compressing and maintaining the pressure of the gas phase is described, which allows you to quickly switch to the next mode, confirmed by the results of experimental studies of the standard.

Control of Liquid Hydrocarbon Combustion Parameters in Burners with Superheated Steam Supply

A numerical simulation of reacting mixture flow in a full-scale combustion chamber of a prototype burner with a fuel-sprayed jet of superheated steam and a controlled excess air ratio was performed based on a verified model. The influence of steam jets on the combustion parameters of the created prototype device was analyzed based on the results, and a comparison with data from various atmospheric burners, including evaporative and spray types, direct-flow and vortex types, and those with natural and forced (regulated) air supply, was made. Various schemes for supplying steam to burner devices were discussed. It was shown that the relative steam consumption is a parameter for controlling the emission of toxic combustion products, such as NOx and CO, for all designs. A high burner performance is achieved when superheated steam is supplied at more than 250 °C with a relative steam flow rate of >0.6. The design features of the burner systems and operational parameters that ensure high thermal and environmental efficiency when burning various types of fuel and waste are identified.

Mechanism of Spontaneous Acceleration of Slow Flame in Channel

This paper is devoted to the numerical analysis of the spontaneous acceleration of a slow flame in a semi-closed channel. In particular, the flow development in the channel ahead of the propagating flame is analyzed. The applied detailed numerical model allows the clear observation of all features intrinsic to the reacting flow evolution in the channel, including the formation of perturbations on the scale of the boundary layer and their further development. In all considered cases, perturbations of the boundary layer emerge in the early stages of flame acceleration and decay afterward. The flow stabilizes more rapidly in a narrow channel, where the velocity profile is close to the Poiseuille profile. At the same time, the compression waves generated in the reaction zone travel along the channel. The interaction between compression waves in the area of combustion products can lead to the formation of shock waves. The effect of shock waves on the flow in the fresh mixture causes an increase in the flame area and a corresponding flame acceleration. In addition, shock waves trigger boundary-layer instability in wide channels. The perturbations of the boundary layer grow and evolve into vortexes, while further vortex–flame interaction leads to significant flame acceleration.

A Multiple-physics coupled model for nanoconfined CO2-CH4 mixture transport behavior: Implications for CO2 geological storage in ultra-tight formation

Considerable efforts have been made to examine the feasibility of CO2-enhanced gas recovery (CO2-EGR), a promising approach for improving gas recovery by using CO2 to displace in-situ CH4 in ultra-tight gas reservoirs rich in nanopores. However, most research has focused on either single-component gas flow physics or competitive adsorption of multiple gas components in nanopores. The flow behavior of nanoconfined CO2-CH4 mixtures remains an area of knowledge gap. This work establishes a theoretical framework for CO2-CH4 mixture flow capacity by coupling mixture flow in the bulk region with surface diffusion in the adsorption area. Results indicate that: a) Total mixture flow conductance increases rapidly at pressures below ∼10 MPa, with CO2 contributing over 99 % to surface diffusion conductance; b) Increasing CO2 molar ratio from 0.2 to 0.8 can lead to a 167 % enhancement in total mixture conductance; c) Variations in CO2-CH4 competitive adsorption characteristics have little impact on total conductance.

Research on fluid flow and heat transfer characteristics in a three-dimensional condenser

The condenser plays a crucial role in nuclear power plants, impacting equipment economics and safety through shell-side two-phase flow and heat transfer. However, existing research has oversimplified the tube bundles, lacking comprehensive information for optimal performance. In this research, a three-dimensional method incorporating mixture and multiphase flow condensation models was used to investigate flow behavior and heat transfer characteristics without simplifying the internal structure. Calculation details were enhanced by omitting the porous medium approach. The numerical model achieved reasonable accuracy when compared to theoretical calculations for a range of steam mass flow rates. Analysis of numerical results, including pressure, velocity, temperature, air mass fraction, and heat transfer coefficient, revealed that steam flow rate and air mass fraction were key factors influencing heat transfer. This research demonstrates the method’s capability to capture intricate calculation details, providing valuable insights for optimization design considerations in condenser performance.

Lattice Boltzmann Model for Rarefied Gaseous Mixture Flows in Three-Dimensional Porous Media Including Knudsen Diffusion

Numerical modeling of gas flows in rarefied regimes is crucial in understanding fluid behavior in microscale applications. Rarefied regimes are characterized by a decrease in molecular collisions, and they lead to unusual phenomena such as gas phase separation, which is not acknowledged in hydrodynamic equations. In this work, numerical investigation of miscible gaseous mixtures in the rarefied regime is performed using a modified lattice Boltzmann model. Slip boundary conditions are adapted to arbitrary geometries. A ray-tracing algorithm-based wall function is implemented to model the non-equilibrium effects in the transition flow regime. The molecular free flow defined by the Knudsen diffusion coefficient is integrated through an effective and asymmetrical binary diffusion coefficient. The numerical model is validated with mass flow measurements through microchannels of different cross-section shapes from the near-continuum to the transition regimes, and gas phase separation is studied within a staggered arrangement of spheres. The influence of porosity and mixture composition on the gas separation effect are analyzed. Numerical results highlight the increase in the degree of gas phase separation with the rarefaction rate and the molecular mass ratio. The various simulations also indicate that geometrical features in porous media have a greater impact on gaseous mixtures’ effective permeability at highly rarefied regimes. Finally, a permeability enhancement factor based on the lightest species of the gaseous mixture is derived.

Thermodynamic and spectroscopic analyses of N-Methyl benzylamine-isomeric amyl alcohol binary mixtures: Jouyban-Acree model correlation and experimental validation

ABSTRACT Excess molar volume, excess isentropic compressibility, deviation in viscosity, and excess Gibbs free energy of activation for viscous flow for binary mixtures of N-Methyl benzyl amine (NMBA) with 2-Methyl-2-butanol (2M2B), 2-Methyl-1-butanol (2M1B), and 3-Methyl-1-butanol (3M1B) were determined from measured densities (ρ), viscosities (η) and speeds of sound (u) at 303.15 K to 313.15 K. Influence Structural disparities on excess properties is discussed concerning intermolecular forces. The Prigogine – Flory – Patterson (PFP) theory identifies predominant molecular interactions, and the Jouyban – Acree model correlates density, speed of sound, and viscosity with composition. Thermodynamic activation parameters were calculated using the Eyring equation to study viscous flow thermodynamics. FT-IR and 1H NMR spectra of equimolar binary mixtures were analysed to confirm experimental findings through absorption bands (cm−1) and chemical shifts.

Numerical simulation of unsteady cloud cavitation in an orifice nozzle by a compressible gas-vapor/liquid mixture cavitation model

Abstract Focused on the behaviour of unsteady cloud cavitation in a submerged orifice nozzle, this work presents a numerical investigation by using a compressible gas-vapor/liquid mixture cavitation model. The mean flow of the two-phase mixture is calculated by URANS for compressible fluid and the intensity of cavitation is evaluated by the gas volumetric void fraction considering the effect of fluid compressibility varying with phase change. Water jets issuing from a submerged orifice nozzle are investigated under different cavitation conditions. Computation results are compared with experiment data and the validity of computation is confirmed. The periodical shedding of cavitation clouds is captured reliably. Numerical simulations reveal that a leading cloud principally split by the shear flow and a subsequent cloud detached by the re-entrant jet are successively shed downstream, and they coalesce over the range of approximately x/d ≈ 2∼3. This process is repeated and the flow rate coefficient pulsates periodically under the effect of cavitation clouds.

Ventilation of large section blind headings under conditions of changing ore load size

Relevance. The need to ensure safe working conditions in the working areas of underground mines. Stagnant zones with low air velocities can be formed in large section blind heading behind the ore bulk when ore is shipped by mining machines. There is a possibility of the formation of local gas accumulations and their abrupt removal later in such stagnant zones due to the unsteadiness of accumulation and transfer of gas impurities in a blind heading. A sharp removal of gas will lead to contamination of the load-haul-dump operators’ workplace. Aim. To identify removal of exhaust gases in large section blind headings in conditions of changing ore load size. Objects. Large section blind headings with of complex geometry. Methods. Three-dimensional numerical simulation of unsteady turbulent flow of a gas-air mixture in the Ansys CFX, visualization and analysis of simulation data in the Wolfram Mathematica. Results. The paper presents the results of mathematical modeling of ventilation of large section blind headings of complex geometry under conditions of changing ore load size formed during mining operations by the load-haul-dump machines with an internal combustion engine. It is shown that either a single vortex is formed that ventilates the blind headings space, or a stagnant zone behind the bulk ore, which is characterized by a relatively low intensity of mass transfer. Vortex formation depends on the height of the ore bulk. The authors have obtained the dependences of the change in the average concentration of exhaust gases at the outlet of the blind headings space on the operating time of the machine. They determined the dependence of the correction volume coefficient on the geometric parameters of the blind headings. An analytical model of the removal of gases from the blind headings space under conditions of changing bulk ore volume is obtained. The expression of increment in gas concentration on an operator’s workplace makes it possible to derive formula to find maximum time of load-haul dump operation in a stope such that gas concentration is never higher than maximum allowable concentration.

Parametric Study on Venturi Pressure Drop for Two Phase Oil (D130)-Water Flow for Different Operating Conditions – An Experimental Investigation

The governing parameters which affect pressure drop of two-phase oil-water flow across the venturi meter are water cut and angle of inclination. The study investigates experimentally the effect of inclination and water cut on pressure drop measurements across different venturi meters with beta ratios (β) = 0.4, and 0.6 for oil–water two-phase flow experiments in a 3-inch pipe for different operating conditions. Two-phase inclinable flow loop has been employed for conducting the experiments for different fluid mixture flow rates and water cuts. The working fluids utilized are Exxsol mineral oil (D130) and potable water. The experiments were conducted for water cuts varying from 0 to 100% in steps of 20%, flow rates ranging from 2000 to 12000 barrels per day (BPD), and for horizontal and vertical flow loop inclinations (0◦ and 90◦). Liquid flow rates considered in the study match flow rates of real oil wells. The results indicate that the venturi pressure drop varies linearly with water cuts for both β ratios (0.4 and 0.6). The study indicates that the effect of inclination on venturi pressure drop is not appreciable for all water cuts and flow rates. Also, from the experimental results it can be concluded that venturi with β = 0.6 is favourable for multiphase flow metering (with flow rates ranging from 8000 to 12000 BPD). The tangible findings of the study will be helpful in combating multi-phase flow challenges in oil and petroleum industries.

Analysis of Application of Cement-Sand Solutions During the Renovation of Road Water-Draining Structures Using Metal Corrugated Structures

Abstract. Problem. Today, the restoration of road culverts using metal corrugated structures is relevant and necessary, as they are in difficult operating conditions, which is the reason for their premature destruction. Goal. Сonducting an analysis of the dynamic viscosity of cement-sand solutions during the restoration of road culverts using metal corrugated constructions. Methodology. The hydraulic resistance analysis of the cement-sand solution during fogging of the inter-pipe gap and the dynamic viscosity analysis of the cement-sand solution were carried out. Results. Based on the conducted research, the need to improve the existing cement-sand solutions for inter-pipe clogging was established. Originality. The work considers the most common approaches to determining the hydraulic resistance to the movement of cement-sand mortar. The dynamic viscosity analysis of the cement-sand solution was performed. Practical value. The work considers the most common models describing the flow of an ordinary cementconcrete mixture (cement-sand mortar). An approach to determining the pressure loss when filling the inter-pipe gap is presented. The paper provides an analysis of the use of cement-sand mortars during the restoration of road culverts using metal corrugated structures. Based on the conducted analysis, the dependence of dynamic viscosity on the composition of the mixture and the water-cement ratio was established. The paper proposes general provisions for the restoration of road culverts using metal corrugated structures with the establishment of requirements for cement-sand mortar.