Local Resistance Coefficient Research Articles

A turbulent flow topology optimization method for diverging tee resistance reduction

The resistance of local components in piping and duct systems significantly affects the energy consumption of fans and pumps, accounting for 40–60 % of the total building energy consumption. In this paper, an improved topology optimization method for variable density turbulent flow is proposed to design a low-resistance diverging tee structure in piping and duct systems. The advantages of the improved optimization method over the traditional method are analyzed using finite element numerical simulation, and the applicability of the proposed method is verified in the Reynolds number range of 0.6 × 105–2.6 × 105. In order to ensure the resistance reduction effect of the topology diverging tee under multiple operating conditions, the local resistance coefficients under nine flow ratios were simulated and calculated using the finite volume method. The results show that the topology diverging tee can significantly reduce the resistance. Compared with the traditional tee, the maximum resistance reduction rates in the straight-through direction and branch direction reached 63 % and 59 %, respectively. In addition, the intensity of secondary flow in five downstream sections was analyzed based on the dimensionless parameter Se. Finally, the actual resistance reduction effect of the topology diverging tee was experimentally verified. The optimization method and analysis results proposed in this study can provide a reference for the optimal design of pipelines with low resistance in energy-saving operation of buildings and in engineering fields such as petroleum and chemical industries.

Research of hydrodynamic processes in the flow part of a low-flow thermopressor

This research explores the hydrodynamic processes within the flow section of a low-flow thermopressor as a jet-type heat exchanger that utilizes the instantaneous evaporation of highly dispersed liquid in accelerated superheated gas flow resulting in reducing gas temperature with minimum resistance losses in contrast to conventional surface heat exchanger. The efficiency of thermopressor, as a contact heat exchanger, is highly dependent on the design of the flow section and the water injection nozzle. Geometric characteristics perform a crucial role in shaping gas-dynamic processes along the length of the thermopressor's flow section, influenced by resistance losses and local resistance in the tapering and expanding channel segments. Therefore, the optimum thermopressor design has to ensure minimize pressure losses. Using Computational Fluid Dynamics (CFD), the prototype thermopressor models were simulated and the results were compared with experimental data. The empirical equations for local resistance coefficients of thermopressor diffuser and confuser were received to evaluate the impact of various design parameters. The obtained local resistance coefficients for the confuser ranged from 0.02 to 0.08 and for the diffuser – from 0.08 to 0.32. The practical recommendations on geometric and operating parameters and characteristics for enhancing the efficiency of hydrodynamic processes in thermopressor flow part were given.

Flow characteristics and resistance coefficients of local components of building heat-moisture-oxygen transport pipelines in the Tibetan Plateau

The Tibetan Plateau is characterized by low-pressure, cold, hypoxic, and dry ambient conditions. Thus, in addition to heating, buildings in the region need humidification and oxygenation. It is noted here that the existing specifications of the resistance coefficients of the gas flow in the HVAC pipeline do not consider the effect of the variation in air components on the local resistance of the pipeline due to the low air pressure conditions as well as the humidification and oxygenation. In this paper, the effects of various parameters on the local resistance loss are investigated and reported, including the atmospheric pressure, inlet velocity, humidity, oxygen concentration, pipe diameter, wall roughness, velocity ratio, and area ratio between the branch and the main pipes. The results showed that the decrease in atmospheric pressure leads to a shorter longitudinal distance of effective dissipation of the secondary flow, primarily concentrated in 25D-27D. Additionally, the resistance losses generated in the elbow, the tee straight branch pipe, and the side branch pipe are reduced, with a maximum reduction of 42 %, 33 %, and 46 %, respectively, under low pressure conditions. Also, with the increase in the inlet velocity and the decrease in the pipe diameter, the local resistance of the elbow pipe is increased by a maximum of 14 times and 22 %. Moreover, when the velocity ratio increases and the area ratio between the branch pipe and the main pipe decreases, the local resistance loss of the straight branch pipe and the side branch pipe increases. Based on this study, the recommended value of the local resistance coefficient of the elbow and tee under low pressure is identified. This can provide a reference for the proper design of heat-moisture-oxygen transport pipelines in the plateau area.

Badania turbulentnego przepływu płynu w pompach głębinowych w celu poprawy bezpieczeństwa środowiskowego

When the plunger moves downwards, the local hydraulic resistance in the injection system causes a hydraulic force from the bottom upwards, which prevents the plunger from falling freely in the cylinder and is the source of the bending of the pump rod column. For this reason, the plunger takes an eccentric position in the cylinder and presses against it, delaying the plunger fall from the head of the balancer of the rocking machine and disturbing coaxial connection of the stock-discharge valve-plunger. These complications lead to increased wear of the plunger-cylinder pair, breakage of the injection valve cell, broken pump rod column, loss of the plunger stroke, etc. It should be noted, however, that in these tests, the flow factor μ is taken as the hydraulic resistance for determining the pressure loss in the valve assembly, and the valve seat cross-section is calculated. When calculating the friction force in the plunger-pressure valve system, the loss of pressure in it is taken to be equal to the loss of pressure of the valve unit. As is known, the downhole pump suction and injection system is a complex system of local resistance, as it consists of different combinations of elements that strongly affect the overall hydraulic resistance of the unit. It is therefore advisable to adopt the local hydraulic resistance coefficient as the hydraulic resistance of the respective unit. The reliability of downhole pumps in general and their individual components is ensured during their design and manufacture and depends on the design features, the quality of manufacturing of components thereof, assembly of the downhole pump in general and their components, as well as a number of other process indicators.

Analysis of Factors Affecting Vacuum Formation and Drainage in the Siphon-Vacuum Drainage Method for Marine Reclamation

Traditional drainage methods for marine reclamation typically consume large amounts of energy and have a negative environmental impact. The siphon-vacuum drainage method (SVD) automatically forms a vacuum and drains using less energy. It has significant potential for research and application. In this study, a theoretical model is used to calculate the vacuum formation process and drainage rate. Qualitative analysis and global sensitivity analysis were conducted to investigate the effect of various factors in the SVD on vacuum formation and drainage. The qualitative analysis suggests that modifying the length and diameter of the siphon pipe and the thickness of the sealing soil column to increase the siphon rate can improve the vacuum degree and drainage efficiency. Sobol global sensitivity analysis reveals that the sealing soil column thickness is the main factor affecting the vacuum, with a first-order sensitivity index accounting for up to 79.48%. The impact of cylinder diameter and the local resistance coefficient (0.43%) can be almost neglected. A fitting equation for estimating the maximum achievable vacuum is provided. Calculations show that the vacuum formed by the SVD can reach over 80 kPa. This work can help optimize SVD design and advance environmentally friendly marine reclamation projects.

Flow field characteristics and energy loss model of the effective upstream flow region of orifice in liquid jet

Orifice jets commonly adhere to the thick-walled orifice jet mechanism or the thin-walled one, where the difference between the two orifice jet mechanisms is generally considered to be caused after the fluid enters the orifice. However, ignoring the energy loss before entering the orifice could be inaccurate and even misleading. Therefore, we studied the flow behavior in the upstream flow region of thick-walled orifices (small orifices) and thin-walled ones (large ones). Firstly, the concept of the effective upstream flow region of orifice was proposed based on the film theory. It can be simplified into an approximate hemispherical multi-channel parallel contractive flow field. Then, the experiments of the effective upstream flow region were conducted by the streamlined contractive orifices with equivalent energy loss. The proportion of the energy loss before the fluid enters the orifice to the total energy loss was obtained. In addition, the maximum impact range of the effective upstream flow region was remarked by theoretical derivation, and local resistance coefficient functions were established based on the CFD simulation results. Finally, a semi-theoretical model of energy loss in this region was developed. It can quantitatively measure the proportion of increased energy consumption caused by the sucked air inside orifice, well verifying the eddy energy consumption, which provides a scientific exclusion method for predicting the complex form resistance.

Influence of the Main Working Parameters and Geometrical Parameters on the Supercritical CO2 Flow Instability in a Heated Tube

Supercritical CO2 (sCO2) flow instability is an issue that must be considered in the reasonable design of sCO2 boiler. Because it can cause equipment vibration and heat transfer deterioration. In this article, a numerical model for the sCO2 flow instability in the single tube was developed. Different from the traditional model, the effects of metal heat storage and axial heat conduction in the tube wall were considered. The influence of main parameters on trans-pseudo-critical number (N TPC) and oscillation period (t 0) was studied, with the tube length (L) from 3 to 11 m and the inner diameter (D in) from 10 to 22 mm. N TPC increases with increasing the inlet pressure (P in), mass flux (G), inclination angle (α), and the inlet local resistance coefficient (K in). N TPC decreases with D in and outlet local resistance coefficient (K out). The effects of the sub-pseudo-critical number (N SUBPC), wall thickness (WT) and L on N TPC are nonlinear. With increasing N SUBPC, WT, L, D in, and K out, t 0 increase. As G, α, and K in increase, t 0 becomes smaller. When N SUBPC is lower than 0.9146, t 0 rises with P in increasing. It is opposite with N SUBPC higher than 0.9146.

Long-term operation optimization of circulating cooling water systems under fouling conditions

Fouling caused by excess metal ions in hard water can negatively impact the performance of the circulating water system (CCWS) by depositing ions on the heat exchanger's surface. Currently, the operation optimization of CCWS often prioritizes short-term flow velocity optimization for minimizing power consumption, without considering fouling. However, low flow velocity promotes fouling. Therefore, it’s crucial to balance fouling and energy/water conservation for optimal CCWS long-term operation. This study proposes a mixed-integer nonlinear programming (MINLP) model to achieve this goal. The model considers fouling in the pipeline, dynamic concentration cycle, and variable frequency drive to optimize the synergy between heat transfer, pressure drop, and fouling. By optimizing the concentration cycle of the CCWS, water conservation and fouling control can be achieved. The model can obtain the optimal operating parameters for different operation intervals, including the number of pumps, frequency, and valve local resistance coefficient. Sensitivity experiments on cycle and environmental temperature reveal that as the cycle increases, the marginal benefits of energy/water conservation decrease. In periods with minimal impact on fouling rate, energy/water conservation can be achieved by increasing the cycle while maintaining a low fouling rate. Overall, the proposed model has significant energy/water saving effects and can comprehensively optimize the CCWS through its incorporation of fouling and cycle optimization.

Расчет коэффициента местного сопротивления при изотермическом течении неньютоновской несжимаемой жидкости в цилиндрическом канале с внезапным сужением

The engineering calculation and construction of the extrusion tool in the form of cylindrical forming channels with sudden narrowing is associated with the determination of the coefficient of resistance of sudden narrowing and local pressure losses. The available theoretical and experimental data on the values of the resistance coefficient of sudden narrowing are contradictory, approximate in nature and, in some cases, do not take into account the rheological properties of the liquid. Their use to calculate local pressure losses under laminar flow conditions leads to significant errors. To eliminate the indicated problems, a mathematical statement of the problem of isothermal stationary laminar flow of non-Newtonian non-compressible fluid in an axisymmetric channel with sudden narrowing was formulated. The mathematical model of flow in spatial formulation is formalized in the form of equations for preserving momentum and mass. As a rheological model, the Carreau model is taken, taking into account the presence of finite viscosity values at marginal shear rates. The numerical solution of the problem was performed by the finite element method using the Comsol MultiphysicsTM CFD modeling package. As a result of the solution, the picture of the current of the non-Newtonian medium was restored in the form of the distribution of current lines, kinematic and dynamic flow parameters. The impact of Reynolds number on change of geometric characteristics of flow structure, kinematic and dynamic flow parameters was evaluated. Values of local resistance coefficient and pressure losses for overcoming sudden narrowing for selected flow modes are calculated. The results of computational experiments are summarized in the form of a criterion ratio for calculating the coefficient of local resistances depending on the Reynolds number.

Local Resistance Characteristics of T-Type Tee Based on Chamfering Treatment

The T-type tee is a crucial part of liquid distribution systems and is widely used in irrigation, drainage, water delivery, and agricultural fertilizer injection, among other areas. Confluence angle, pipe diameter ratio, and flow rate ratio have been the main focus of previous research. Research on the hydraulic characteristics and resistance optimization brought about by the main-side pipe intersection’s chamfering treatment is, nevertheless, incredibly rare. Optimizing the structure of the T-type tee could improve its sustainability in many aspects, such as its energy consumption, durability, and production process. In order to fill this void in the literature, the current investigation concentrated on the resistance reduction and flow properties of T-type tees by means of chamfering treatment. Using a newly proposed coefficient called the integrated local resistance coefficient, the integral flow characteristics and resistance reduction effects of T-type tees were addressed. Through the use of the verified computational fluid dynamics (CFD) method, the crossed effects of five chamfer ratios (R = 0D, 0.5D, 1D, 2D, and 3D), nine flow rate ratios (0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, and 0.9), and two pipe diameter ratios were examined. When the Reynolds number exceeded 3 × 105, the flow remained in the quadratic drag region, meaning that the local resistance coefficient of T-type tees was no longer dependent on the flow velocity. In both confluence and shunt conditions for equal tees, chamfering treatment was proven to be an efficient method for reducing local resistance under these conditions. For instance, following a 1D chamfering treatment on the T-type confluence tee, at a flow ratio of 0.5, the local resistance coefficients ζ1 and ζ2 dropped by 68% and 82%, respectively, in comparison to the 0D condition. The effects of resistance reduction were improved by a wider chamfer radius and a higher side pipe flow rate ratio. The highest overall performance was obtained by chamfering a T-type tee with a curvature radius of 1D, taking into account flow characteristics, sustainability, processing technology, economic cost, and promotion difficulties. The chamfering procedure produced a more noticeable reduction in resistance for unequal tees with comparable velocities in the main and side pipes when the pipe diameter ratio was greater than 0.5.

Steam-side heat transfer analysis in spirally corrugated tube for grate furnace superheater

In the case of low Reynolds number, the structure of the spirally corrugated tube will make the solid particles in the fluid be affected by the centrifugal force, and be more evenly distributed in the fluid to achieve anti-fouling effect. Therefore, it can be used in heat exchangers with serious fouling problems to improve heat exchange efficiency. In this paper, the first stage low-temperature superheater in the grate furnace is selected as application equipment. The local resistance coefficient, local Nusselt number and local heat flux are analyzed, the thermal-hydraulic characteristics of different sample points are evaluated. Combinatorial method of central composite design and Latin hypercube design is used to select four representative sample points, and effect of the corrugation pitch ratio and depth ratio on the convective heat transfer intensity, fluid resistance and fluid work consumption of the steam side is studied. The research results show that as the corrugation depth increases, the local heat transfer coefficient in the circumferential direction increases, and more heat is transferred from the flue gas to the steam, but the pump power consumed in the flow process has also increased. Due to the existence of spiral structure, the local heat flux density of the wall is symmetrically distributed in the circumferential direction, which represents that the temperature gradient increases, and the heat flow is improved.

Real values of local resistance coefficients during water flow through a pipe aerator with filling

Real values of local resistance coefficients during water flow through a pipe aerator with filling

A Hybrid Prediction Model for Local Resistance Coefficient of Water Transmission Tunnel Maintenance Ventilation Based on Machine Learning

Multiple ducts in the working shaft and main body of tunnels form a combined tee structure. An efficient and accurate prediction method for the local resistance coefficient is the key to the design and optimization of the maintenance ventilation scheme. However, most existing studies use numerical simulations and model experiments to analyze the local resistance characteristics of specific structures and calculate the local resistance coefficient under specific ventilation conditions. Therefore, there are shortcomings of low efficiency and high cost in the ventilation scheme optimization when considering the influence of the local resistance. This paper proposes a hybrid prediction model for the local resistance coefficient of water transmission tunnel maintenance ventilation based on machine learning. The hybrid prediction model introduces the hybrid kernel into a relevance vector machine to build the hybrid kernel relevance vector machine model (HKRVM). The improved artificial jellyfish search algorithm (IAJS), which utilizes Fuch chaotic mapping, lens-imaging reverse learning, and adaptive hybrid mutation strategies to improve the algorithm performance, is applied to the kernel parameter optimization of the HKRVM model. The results of a case study show that the method proposed in this paper can achieve the efficient and accurate prediction of the local resistance coefficient of maintenance ventilation and improve the prediction accuracy and prediction efficiency to a certain extent. The method proposed in this paper provides a new concept for the prediction of the ventilation local resistance coefficient and can further provide an efficient prediction method for the design and optimization of maintenance ventilation schemes.

A local resistance coefficient model of aircraft hydraulics bent pipe using laser powder bed fusion additive manufacturing

Laser powder bed fusion (L-PBF) technology has remarkable advantages in achieving lightweight and miniaturized products, and a short manufacturing cycle. However, for the inner suface of L-PBF bent pipe, the distribution of surface roughness is not uniform. The surface roughness at the top of the bent pipe is much greater than that of other positions, which results that the local resistance coefficient of the bent pipe manufactured by L-PBF cannot be estimated accurately through the existing theory dedicated for conventional pipelines. Aiming at resolving this shortcoming, a new model is proposed to predict the local resistance coefficient of aircraft hydraulic bent pipes. In this regard, numerous 90°-bend Ti6Al4V (TC4) pipelines with different diameter-bend ratios (D/R) are fabricated using the L-PBF technique, and the geometry and surface roughness of the machined samples are measured experimentally and calculated numerically. Based on the obtained results from the finite element simulation and measurements from the experiment for local resistance coefficients of various bent pipes, a model is established to predict local resistance coefficients. The obtained results indicate that the surface roughness, Reynolds number, and diameter-bend ratios affect the local resistance coefficient of the bent pipe. Transition between flow regimes is observed in L-PBF bent pipes. The Reynolds number range in the transition region increases with the decrease of surface roughness, and the critical value of the transition region is modeled. Compared with the experimental data, the predicted values have an average error of less than 10%, indicating that the prediction accuracy is greatly improved.

К вопросу определения гидравлических сопротивлений тройников металлополимерных трубопроводов

The purpose of the conducted studies is experimental determination of hydraulic resistances of asymmetrical equal-pass tees with α=90° angle in the metal-polymer pipeline, identification of dependencies of local resistance coefficients ζ on the ratio of flow rates of direct passage Q2 and flow rates of assembly hose Q3, their comparison with existing reference data and theoretical dependencies. The article presents the results of experiments and analysis to determine hydraulic resistances in the metal polymer pipeline, provides the method of theoretical determination of resistance coefficients in the metal polymer pipeline VALTEC ISO and the method of determining the values of local hydraulic resistances of an asymmetric equal-pass (supply) T-joint with an angle of α=90•°. The obtained empirical dependencies of the values of the local resistance coefficients of the ζ=f(Q2/Q3) in the asymmetric equal-pass tee with an angle of α=90° in the metal-polymer pipeline from the ratio of the separated flows Q2/Q3 to the branch upwards, to the passage in the straight tee and the division of flows atd ifferent internal diameters of the VALTEC ISO pipeline for the range of Reynolds numbers Re =1⋅104 ÷ 3,2 ⋅104 are presented. The obtained empirical relationships were compared with reference data on formulas and experimental data for standard tees with angle α = 90° and tees made of ductile iron on thread α = 90° when dividing liquid flows.

Local Resistances of Gas–Liquid Two-Phase Flows in Vertical L-Shaped and Z-Shaped Pipes

In this paper, a systematic numerical study of the local resistance coefficients of vertical L-shaped and Z-shaped pipes for gas‒liquid two-phase flows under vertical conditions was carried out using a realizable k-ε turbulence model combined with a mixture model in Fluent software. Specifically, the influence of the Reynolds number Rel, the gas-phase volume rate α, the radius–diameter ratio R/D, the height–diameter ratio H/D, and the two-phase flow direction on the local resistance coefficient ξ were discussed in detail. ξ of the vertical Z-shaped pipe decreases with increasing Rel, while ξ of the vertical L-shaped pipe does not change significantly. In a specific range, ξ of vertical L-shaped and Z-shaped pipes increases with increasing α and decreases with increasing R/D. In Z-shaped pipes, under the upward flow condition, ξ increases with increasing H/D, and under the downward flow and horizontal flow conditions, ξ first decreases and then increases with increasing H/D. Overall, upward and downward flow conditions have a larger ξ than the horizontal flow condition. When H/D is larger than 14, ξ tends to be stable under all three flow conditions. Finally, the relationship equations between ξ and Rel, α, R/D, and H/D were fitted, which agreed with the numerical results.

Analytical Assessment of Valve Throughput Coefficient

The current level of industry development for the gas and oil production of equipment requires the development of engineering methods for calculating the hydraulic characteristics of manufactured products. Due to the complexity of the designs of distribution and control units for oil and gas transportation networks, the hydraulic characteristics of their control components increasingly affect the performance of regulation. In the construction of distribution and control units, pipeline fittings are used, in particular, wedge gate valves and shut-off valves. One of the main hydraulic characteristics of these products is the throughput, which is assessed by the throughput coefficient. Therefore, now the design engineer needs simple and accurate methods to determine the theoretical value of the throughput coefficient at the design stages of the product. The throughput is related to the hydraulic resistance of the passage part of the pipeline fittings, because it affects the level of pressure reduction when fluid moves from the inlet to the outlet of the product. There are methods for determining local hydraulic resistance caused by a change in the geometry of the passageway, based on the Weisbach formula and empirically determined local resistance coefficients. Engineering methods are proposed for determining the throughput coefficient of two types of pipeline fittings - a wedge valve and a shut-off valve. The methods are based on a well-established approach, expressed in the use of the connection of the throughput with a set of local hydraulic resistances that arise in the path of the working medium. The methods use information about the values of local hydraulic resistance values obtained empirically with the possibility of their approximation to obtain intermediate values of these indicators. The geometric features of the passage channels of the products under consideration are taken into account. They are compared with the existing nomenclature of information about the values of the coefficients of local hydraulic resistance. The proposed methods make it possible to reduce the time for carrying out calculations with obtaining a result whose accuracy is sufficient for use in engineering calculations. Expressions are obtained that allow determining the values of the throughput coefficient of the wedge gate valve and the shut-off valve, taking into account the geometric features and the relative position of the flow sections of pipeline valves, as well as the physical properties of the working medium.

Air distribution efficiency improving in the premises by rectangular air streams

Abstract This article discusses the topical issue of improving the distribution of air in the premise due to application of the all type rectangular air streams: flat, axisymmetric and rectangular ones. The purpose of the article is research of the all types rectangular air streams, analytical dependencies obtaining for determination of the air velocity attenuation coefficient, aerodynamic local resistance coefficient and noise level from the ratio of slit length to its height; optimization of the inflow slit side's ratio. It has been established that increase of the inflow slit sides ratio results in the air velocity attenuation coefficient decrease and results in increase of the noise level and resistance coefficient of the rectangular slit. The optimal ratio of the sides of a rectangular slit is determined by the combination of aerodynamics and energetics, as well as of the sound power level.

Вплив форми і розмірів стабілізаторів полум’я камери згорання прямоточного типу на гідравлічні характеристики

Direct-flow combustion chambers are afterburner combustion chambers, which are used to short-term increase the thrust of a gas turbine engine for takeoff, maneuvering and overcoming the sound barrier by an aircraft and its flight at supersonic speed. Also, direct-flow combustion chambers are used as part of ramjet engines as the main combustion chambers, in which the process of fuel combustion and heat supply to the working fluid is ensured. Because to solve the problem of theoretical study of total pressure losses with local hydraulic resistance of the front device of a direct-flow combustion chamber in the form of a lattice of V-shaped stabilizers, a mathematical model for calculating the value of the local hydraulic resistance coefficient was formed. It was found that the coefficient of local hydraulic resistance of the lattice of V-shaped stabilizers depends on the degree of shading of the flow by stabilizers and the angle at the top of the V-shaped flame stabilizers. An analysis was made of the influence of the size and shape of the flame stabilizers of the front device on the hydraulic characteristics. Because of the analysis, it was found that the coefficient of local hydraulic resistance depends on the angle at the top of the V-shaped stabilizer almost linearly, and the rate of increase in the coefficient of local hydraulic resistance increases as the degree of shading increases. The coefficients of local hydraulic resistance calculated according to the developed mathematical model agree satisfactorily with the experimental data. The use of the developed mathematical model for calculating the coefficient of local hydraulic resistance is possible within the framework of the front device geometric dimensions and the combustion chamber length method selection at the initial stages of designing.

Resistance reduction of an elbow with a guide vane based on the field synergy principle and viscous dissipation analysis

In recent years, to reduce carbon emissions and increase energy efficiency, the local resistance represented by elbows in piping has received increasing attention in heating, cooling, and water supply systems. In this paper, a resistance reduction method is proposed for a novel low-resistance elbow with a guide vane. The reasonable form for inserting the guide vane is determined. The resistance reduction mechanism of the elbow is analyzed through the field synergy principle and the viscous dissipation principle. The local resistance coefficients of traditional and novel vaned elbows with different diameters and radii of curvature are compared. The resistance reduction effect of the elbow with a 60° guide vane in this study is also compared with that of the elbow with a 90° guide vane from Ito. The results indicate that the insertion of the optimal guide vane improves the synergy between the pressure gradient and the velocity vector downstream of the elbow and reduces the internal energy consumption caused by viscous dissipation. At different inlet Reynolds numbers, the effectiveness of the resistance reduction method is verified. The resistance reduction rate and average synergy angle no longer change when the inlet Reynolds number exceeds 2.5 × 105, and the resistance reduction rate can reach up to 20.1%. When the ratio of the curvature radii to the diameter is R/D = 1, the resistance reduction rate of the elbow with a 60° guide vane is as high as 25.1%. This paper can provide a reference for research on the resistance reduction of local components of heating, cooling, and water supply pipelines.