Simple Calculation Method Research Articles

Safe Mooring of Ships Under the Influence of Wind and Currents

In this paper, the simplified calculation method in the "Load Code for harbor Engineering" to quickly calculate the force on moored ship's lines and wharf bollards under the influence of wind and currents is introduced. In view of the fact that real ship had happened mooring lines breakage accident at berth under ballast condition, use the actual ship X moored at NBGB wharf as an example to verify and calculate the force on ship’s lines and wharf bollards when the ship suffers the most adverse influence. The result show that when the ship encounters a gale (class 8) and a current (velocity 2.6 knot) in ballast condition, some of the mooring lines are subjected to forces close to their breaking strength under the combined effect of wind and current. If there is uneven force on the mooring lines, the possibility of mooring line breakage is great, which is consistent with the actual situation. By calculating and analyzing, give the ship’s mooring stabilize conditions under specific environment. The calculation method in this paper facilitates the captain to judge whether the ship can be safely and steadily moored, and facilitates the port to make clear regulations on the ship’s mooring stabilize according to the actual situation of the berth, which provides important theoretical support for the decision of stability and safety of the moored ship, the proposed preventive measures for the safety risks of stability and safety have reference value for improving the safe operation efficiency for the ship and the terminal.

Study on the load-carrying capacity of an innovative cold-formed steel floor system

To account for the higher structural ductility requirement and higher load-bearing capacity and stability requirements of floor-to-wall connections of mid-rise cold-formed steel (CFS) structures, an innovative CFS floor system with gridded beams and filler blocks (BB-based CFS floor system, where BB stands for “beams” and “blocks”, respectively) was first proposed. Then, experimental and refined numerical simulation studies were performed to investigate the flexural behaviour of the floor system. Afterwards, a simplified calculation method of the load-carrying capacity of the floor system was deduced based on its mechanical mechanism. The results show that (1) the deformation of the floorboard-to-beam screw connections and the relative buckling of the compression beam flange and adjacent web are the primary reasons for the nonlinear load-deflection relationship and bending failure of the floor system. (2) Compared with the existing CFS composite floor systems, the combination effect of each component in the BB-based CFS floor system prevented the beams from unstable failure after losing the restraint of floorboards, thereby effectively improving the load-carrying capacity and nondeformability of the floor system. (3) After decomposing the BB-based CFS floor system into composite floor beams, the load-carrying capacities of the floor system can be determined simply according to the cumulative flexural bearing capacities of these composite floor beams based on plasticity theory, the relative errors between the deduced load-carrying capacities and the test results and simulated results of different BB-based CFS floor systems are within 10%, and the calculated results are relatively safe.

Optimization design research of insulation thickness of exterior wall based on the orientation difference of solar radiation intensity

Different from the traditional isotropic insulation design which aims at reducing building heat loss, a new anisotropic insulation design method which fully considers the orientation difference of solar irradiation is proposed for the purpose of reducing indoor radiant thermal discomfort. Based on the principle of equal heat flux intensity of the envelope, a simplified calculation method of the insulation thickness in each orientation is established. The relationship between each orientation insulation thickness can be simplified as a linear relationship. The influence characteristics between the factors like exterior surface, brick wall thickness, brick and insulation material and the orientation differential insulation thickness are obtained. Six typical cities in China are selected in combination with solar energy resource zones and building thermal divisions, and the insulation thickness of building envelope in each region is calculated. The results show that the orientation differential insulation design mode is suitable for solar energy resource zone I and zone II. Taking Lhasa as an example, compared with isotropic thermal insulation conditions, the material cost of thermal insulation layer under orientation differential insulation conditions is reduced by 24.6%, and the average heating energy consumption increases only by 6.1%. When the insulation material is the same, the average heating energy consumption can be reduced by 9.0%. The results can provide a reliable basis for the application of orientation differential insulation technology in rich areas of solar energy resource.

An Enhanced Adaptive Large Neighborhood Search for Unrelated Parallel Machine Scheduling With Sequence Dependent Setup Times

The unrelated parallel machine scheduling problem with sequence dependent setup times (UPMSP-SDST) addressed in this study refers to allocating jobs among a given number of machines and determining their processing sequence on each machine, to minimize the makespan (i.e., the maximum completion time). To deal with large-scale UPMSP-SDST with higher efficiency, this study presents an enhanced adaptive large neighborhood search (EALNS) algorithm with various destroy and repair operators and an efficiency-enhancement mechanism. The efficiency-enhancement mechanism is mainly composed of a simplified calculation method and a hierarchical comparison mechanism, which are applied to improve the implementation process of the greedy-based operators. The simplified calculation method obtains a new makespan by an incremental or decremental transformation, to avoid reluctant calculations. The hierarchical mechanism refines the comparison of different removal or insertion strategies of the operators, thereby arresting high-quality solutions with more metrics. The proposed algorithm is tested on 1640 instances, and numerical results demonstrate the superior performance of the EALNS over the existing methods, especially for large-scale problems. Notably, 834 instances ’ best-known solutions are updated from this study. In addition, deep analysis of the impact of the distribution of setup time on the performance of the algorithm is provided, which further verifies the potential wide applicability of the proposed EALNS.

Theoretical Calculation of the Gravitational Constant Using The Elementary Charge, Speed of Light, Z Boson Mass, and Relativistic Mechanics

The gravitational constant is an unchanging quantity included in the law of universal gravitation. The value of this constant is known much less accurately than other fundamental physical constants, which is due to the experimental difficulties of measuring it. Here we report a simple method for the theoretical calculation of the gravitational constant using the elementary charge, speed of light, Z boson mass, and relativistic mechanics.

A shortcut for preparing doses of positive inotropic drug infusions in emergency patient management—"fast inotrope bag (FiB) coefficient''

The most basic rule for the management of patients in the emergency departments (EDs) and critical & intensive units (ICUs) are quick decision and quick order medication. For this reason, calculator applications are a necessary part of EDs in order to calculate some drug doses quickly. With the simple formula we discovered, it will be much easier to place an order for the 4 most frequently used drugs of the EDs (dopamine, dobutamine, norepinephrine, epinephrine). We recommend this simple and fast calculation method to all EDs and ICUs with fast inotrope bag (FiB) coefficient. This coefficient has been developed especially for simple pump devices or dosing devices that do not use ready-made inotropic drug bags and that, if needed, first control the preparation of the solution and then the hourly infusion of the prepared solution. These devices are used only because the amount of solution to be given to the patient per hour can be monitored. Taking advantage of this coefficient, the inotrope needed by the patient can be administered easily and quickly with only the patient’s weight information, and the initial dose corresponds to the dose range recommended by the guidelines for inotropes.

MAXIMUM SEISMIC RESPONSE PREDICTION BASED ON CAPACITY SPECTRUM METHOD FOR VIBRATION-CONTROLLED CEILING STRUCTURE EMPLOYED PULLEY MECHANISM

This paper proposes a new procedure for predicting the maximum seismic response based on the capacity spectrum method (CSM) for the passively controlled suspended ceiling structures named “Pulley Damper Ceiling System (PDCS)”. The structural system has a supplemental nonlinear viscous damper and a bilinear hysteretic damper in parallel with displacement amplification mechanisms of block and tackle pulley system. The single degree-of-freedom model of the PDCS is initially discussed. The accuracy of a simplified calculation method for obtaining the structural equivalent damping coefficient, determined by the sum of the inherent damping and the square root of sum of squares (SRSS) of each damping provided by the nonlinear viscous damper and the bilinear hysteretic damper, is verified by comparing with the full-scale shake table test results of the PDCS. Then, the pseudo capacity curve of the structure is generated by continuously plotting the transition of maximum force and displacement values under different amplitudes of sinusoidal waves. Finally, the availability of the response prediction based on proposed CSM procedure considering floor response spectrum (FRS) is examined by the comparison of time history analysis results, and the sufficient accuracy to evaluate the seismic response is confirmed.

THE PROBLEM OF PRODUCTIVITY INCREASE OF THE UNSTRESSED KEYWAYS JOINTS

This paper reports the location of stress concentration and compares the results obtained by theoretical analysis with the analysis done by the analysis software. In order to avoid economic losses of production due to stoppages related to repair work, there is a need to study the development of measures to increase their reliability. Despite knowing the importance of this a very little research work has been reported in this field. An appropriate analysis of the literature was carried out in order to find directions for improving methods performance of keyed joints. The paper analyzes the features of the work of the most common non-stressed connections prismatic keys. Analysis of the state of operation of non-stressed keyed joints, directions for improving their designs, and modern simplified method of calculation explains the relevance of studies of workability and reliability improvement. Ways have been considered to increase the reliability of connections with prismatic keys. In this work, a review of some of the latest, most interesting, by the author's opinion, is carried out, studies on the contact interaction of parts. The requirements for the development and research of new keyed joints are formulated. The basic design of the connection with cylindrical working surfaces of the key is adopted. Known methods of determination are analyzed contact deformations by various scientific schools. The requirements for the development of the method of calculating unstressed keyways are formulated connections. All our calculations were primarily made based on the method of the Scientific School of Volgograd State Technical University and it was adopted as the basic one. Key words: non-stressed keyed connections, unstressed keyed connections, reliability, keyway connection with a cylindrical segment, contact deformation, destruction, improvement of the design, self-locking of the key, fracture

Mechanical characteristics and stability analysis of surrounding rock reinforcement in rectangular roadway

The stability of surrounding rock with bolt support depends on the stability within the reinforcement range. To understand the reinforcing mechanism of a rectangular roadway bolt fully and accurately, a quantitative method for evaluating the stability of the surrounding rock of a rectangular roadway must be developed. First, a roof beam model of a rectangular tunnel is established according to the deformation law of surrounding rock. Based on the elastic–plastic theory, the deflection calculation formula can be derived, and the ultimate load of the roof beam can be obtained under the plastic state without support. Second, based on the reinforcement effect of bolts, a model of a surrounding rock reinforcement body is established, the physical and mechanical properties of this body are deduced, and a method for evaluating the stability of surrounding rock is derived. Finally, by considering actual engineering cases, the theoretical calculation results of surrounding rock deformation are compared with the numerical simulation and field monitoring results. Moreover, the influence of different parameters of the bolt support on the mechanical characteristics and stability of reinforcement is investigated. The results show that the theoretical calculations approximate the numerical simulation and field monitoring values, thus verifying the rationality of the theory. The physical and mechanical properties and stability of the surrounding rock reinforcement body are considerably affected by changes in bolt length and spacing. The anchor design must apply the following principle: the bolt must either be long and sparsely spaced or short and densely spaced. The theory presented in this paper provides a relatively simple and fast quantitative calculation method for the study of the surrounding rock stability of bolt-supported rectangular roadways.

Fatigue life analysis of rotary drill pipe

In this paper, the crack problem of a certain type of rotary drill pipe in use is studied, and a simplified calculation method for the fatigue life of rotary drill pipe is proposed. The bench test device built can be used for the fatigue life test of all tubular structures by analogy. The calculation method of fatigue life of rotary drill pipe is studied through field test and bench test of drill pipe. Firstly, a simplified model of the drill pipe was established with the outer rod of the rotary drill pipe as the research object, and the model was verified. Then, the difference between the hot spot stress extrapolation method recommended by the IIW standard and the DNV standard was compared, and the hot spot stress of the drill pipe was calculated by the two-point linear extrapolation method recommended by the IIW standard, and the equivalent fatigue limit of the drill pipe was obtained by the Von Mises criterion. Finally, the equivalent load was deduced according to the stress level of the actual work test, and the constant amplitude load test was carried out on the bench, and the fatigue life of the drill pipe under the constant amplitude load was obtained. The results show that both the simplified model of the drill pipe and the bench test drill pipe can well reflect the stress level of the field test. The rotary drill pipe mainly bears torsional load, and the crack position of the bench test corresponds to the actual drill pipe crack position. The fatigue life of drill pipe is calculated by applying the Von Mises criterion and Basquin's SN curve power function. The calculated fatigue life is consistent with the results of the bench test. The calculation method can be well applied to the life analysis problem of multiaxial fatigue of large structural parts.

Evaluation method of surrounding rock stability: Failure approach index theory of strain limit analysis for engineering applications.

In general, the ultimate parameter selection method of the failure approach index theory among the three-dimensional problems in geotechnical engineering is unclear in theory, and the symbol convention of the failure approach index in engineering calculation is contrary to the stipulation of the numerical simulation software. Hence, the values of the ultimate plastic shear strain are difficult to determine. To solve this problem, the criterion of positive tension and negative compression and the sequence of the principal stress σ1 ≤ σ2 ≤ σ3 are defined in this paper, and the expression of Mohr-Coulomb yield approach index id deduced. Under the condition of the principal strain sequence ε1 ≤ ε2 ≤ ε3, the formula of the ultimate shear strain is derived using the method of the ultimate strain analysis so as to obtain the simple expression and calculation method of the ultimate plastic shear strain, which has provided the calculation parameters for the three-dimensional ultimate plastic shear strain in the Mohr-Coulomb strain softening model and improved the failure approach index theory. In the light of the aforementioned theory, the ultimate strains of cubic concrete specimens are analyzed, and the obtained ultimate strain values are found consistent with previous research findings, which verifies the correctness and reliability of the ultimate strain analysis method. In addition, it is applied to the quantitative elastic-plastic failure analysis of the section coal pillar in Hengjin coal industry for determining its reasonable retainment width. Consequently, the research results can be embraced as the theoretical basis for the stability analysis of geotechnical materials and exhibits engineering application potential.

Dynamic Characteristic and Parameter Analysis of a Modular Building with Suspended Floors

Over the past few years, modular buildings have become an important form of environmentally friendly architecture. Prefabricated construction methods have gained a lot of attention because they produce less construction waste and require less labor and water. However, the seismic performance of modular buildings needs to be improved. This paper proposes a prefabricated steel module with a suspended floor, which is based on a multi-tuned mass damped floor system. This paper also derives the form of a motion equation which is unified with the construction process of modular buildings, which can describe the change law of the mass, stiffness, and damping matrix of the structure in the processes of connecting the main structure with the suspended floor slab and of joining different floors. Since the performances of tuned mass damping devices are closely related to the dynamic characteristics of the structure, this paper uses ABAQUS for numerical analysis and mathematical induction (MI) to propose and verify a simplified method for calculating the lateral stiffness of the entire story from a single module’s lateral stiffness. Based on the principle of reducing the stiffness difference in the structure along different directions, a standard scheme of the horizontal extension of the module building is also specified. The results show that the simplified calculation method is reasonable and that the lateral stiffness of the structure increases linearly with the number of modules. Finally, the recommended values for the tuned frequency ratio and tuned damping ratio are given by investigating the dynamic response of the structure under Gaussian white noise excitation. The results show that the recommended tuning frequency ratio and damping ratio ranges in modular buildings are close to those for FIS buildings.

Development of FEM Calculation Methods to Analyse Subcooled Boiling Heat Transfer in Minichannels Based on Experimental Results

Even though two-phase heat transfer of refrigerants in minichannel heat sinks has been studied extensively, there is still a demand for improvements in overall thermal performance of miniature heat transfer exchangers. Experimental investigation and sophisticated heat transfer calculations with respect to heat transfer devices are still needed. In this work, a time-dependent experimental study of subcooled boiling was carried out for FC-72 flow in a heat sink, comprising of five asymmetrically heated minichannels. The heater surface temperature was continuously monitored by an infrared camera. The boiling heat transfer characteristics were investigated and the effect of the mass flow rate on the heat transfer coefficient was studied. In order to solve the heat transfer problem related to time-dependent flow boiling, two numerical methods, based on the FEM were applied, and based on the Trefftz functions (FEMT) and using the ADINA program. The results achieved with these two calculation methods were explored with an emphasis on the impact of the mass flow rate (range from 5 to 55 kg/h) on the resulting heat transfer coefficient. It was found that, with increasing mass flow, the heat transfer coefficient increased. Good agreement was found between the heat transfer coefficients, determined according to two numerical methods and the simple 1D calculation method.

A degree-day model for forecasting adult phenology of Popillia japonica (Coleoptera: Scarabaeidae) in a temperate climate.

Japanese beetle, Popillia japonica (Newman), was first detected in the United States in New Jersey in 1916. The beetle gradually spread to the Midwest U.S. region, and was first confirmed in Minnesota in the late 1960's. Popillia japonica has subsequently become a major invasive insect pest in turfgrass and several agricultural crops. As P. japonica continues to spread throughout the U.S., and other countries, it is important to develop efficient ways to monitor adult populations, and where possible, forecast the phenology of adult population dynamics. During 2019-2021, field trials were conducted to develop a degree-day model that can be used to forecast P. japonica adult phenology under Minnesota, and Midwest summer climatic conditions in. We used commercially available traps and lures to monitor adult flight phenology, specifically beetle trap-catch, along with weather data at four locations in Minnesota, to relate ambient field temperatures to population phenology. The concordance correlation coefficient (CCC), an index of both precision and accuracy, was used to develop a final degree-day model. Model development included evaluation of simple and sine-wave degree-day calculation methods, start dates between 1 Jan. and 1 April, and a range of lower (0-15 °C) and upper (20-37 °C) thresholds. The optimum model was found to be a simple degree-day calculation, using a biofix date of 1 Jan, and lower and upper thresholds of 15 and 21.7 °C, respectively, for predicting 10% beetle trap-catch. The model will aid in future integrated pest management (IPM) and regulatory strategies by providing a tool for prediction of P. japonica adult flight phenology.

Axial compressive behavior of geopolymer recycled brick aggregate concrete-filled steel tubular slender columns

Geopolymer and recycled brick aggregates are applied into the concrete-filled steel tubular column to provide a promising solution to environmental sustainability. This paper investigates the mechanical behavior of geopolymer recycled brick aggregate concrete-filled steel tubular (GRBAC-FST) slender columns under axial compression. Apart from cross-section type, the replacement ratio of brick aggregates (BA) and slenderness ratio are also selected as the main variables. The analysis of the failure mode, bearing capacity, deformation behavior, and strain behavior is conducted. A modified stress–strain model for the GRBAC-FST slender column is proposed and validated, then the parametric analysis on φ-λ relation curves is performed to propose a simplified calculation method for the bearing capacity. Results demonstrate that GRBAC-FST slender columns exhibit obvious lateral deflection, and mid-span bulging of steel tube. Compared with square specimens, circular specimens exhibit plane fracture of concrete, and developed higher bearing capacity and better plastic deformation capacity. The ultimate strength of GRBAC-FST slender columns decreases with the increase of the replacement ratio of BA and slenderness ratio. The stability coefficient φ decreases with the increase of the slenderness ratio, the yield strength of the steel tube and the concrete strength, while it was little affected by the steel ratio. The modified stress–strain model could well reflect the full-range response of GRBAC-FST slender columns under axial loading. The proposed calculation method could be used for the compressive bearing capacity of GRBACFST slender columns, with satisfying accuracy and efficiency.

A simplified calculation method on the smoke back-layering length and inlet air velocity in a tilted tunnel fire without shaft

In a tilted tunnel fire, the inlet air velocity caused by the stack effect at the entrance of the tunnel would be beneficial to smoke control whether the longitudinal ventilation system is used or not. This paper conducted the simulation to investigate the smoke spread behaviours caused by fires in tilted tunnels with natural ventilation. The expression of the smoke back-layering length and the inlet air velocity induced by fires were deduced in the tilted tunnel fire scenarios by the method of dimensional analysis. The effect of various tunnel slopes (5–15%) on the smoke behaviours characteristics and the inlet air velocity were specifically considered. The proposed correlation reveals that the dimensionless back-layering length is independent of the heat release rate (HRR) and its relationship with the tunnel slope is proportional to −1.96 power. The established equation reveals that the dimensionless inlet air velocity is proportional to 0.31 power of the dimensionless HRR and it increases exponentially with the tunnel slope. This research on this topic may contribute to optimize the application of natural ventilation systems or mechanical ventilation in tilted tunnels.

Statistical determination of fracture parameters of concrete with wide variation of water-cement ratio

The size effect and boundary effect fracture models were used to determine the fracture parameters of quasi-brittle materials through geometrically similar and non-geometrically similar specimens. Combining the characteristics of size effect and boundary effect, the concept of relative size was proposed. The simplified calculation method for quantitatively determining the fictitious crack growth length of concrete specimens with wide variation range of water-cement ratio under peak load. Based on the fracture test results of actual concrete, the tensile strength and fracture toughness of concrete with different water-cement ratios can be determined simultaneously. Using the normal distribution function, fracture curves with upper and lower limits covering all test data was established. According to the fracture failure curve, the minimum theoretical size of concrete specimens with different water-cement ratios satisfying linear elastic fracture mechanic was obtained. Furthermore, an analytical formula was established to directly determine the fracture parameters of concrete with different water-cement ratios from the peak load, and based on the analytical formula, the peak state of a large size structure meeting linear elastic fracture mechanic was predicted • The fracture toughness and tensile strength of concrete with different water-cement ratios can be determined by the proposed model in this paper. • The simplified calculation method of fictitious crack expansion Δafic for concrete samples with different water-cement ratio by determining peak load was quantitatively studied. • The relationship between the peak load and the fracture parameters is established, and the prediction of the peak state of the large-size specimen met LEFM was realized.

Numerical Investigation on the Dynamic Response and Fatigue Analysis of the Tension Insulator String Under Stochastic Wind

The tension insulator string is an important component for transferring the load of the conductor to the transmission tower. The damage of tension insulator strings may dramatically affect the operation safety of the grid power. In this paper, the dynamic response and fatigue life of the tension insulator strings under stochastic wind were systematically studied. Firstly, finite element models of conductors and the tension insulator string upon the actual transmission lines were established. The effects of height difference ratios on the dynamic tension of conductors and the dynamic response of tension insulator strings under a 10 m/s stochastic wind were investigated, respectively. Secondly, a simplified calculation method of stress time history is proposed to simplify the fatigue life analysis for tension insulator strings. Finally, based on the Rayleigh distribution, wind farms with the annual mean wind speed of 7 m/s were established to evaluate the fatigue life of tension insulator strings. The stress results revealed the at-risk parts in tension insulator strings and their failure modes. The fatigue life results showed 17.1 and 33.4 years for the GD (Guan Dian)-fittings and the upper U-shackles, respectively. This study can provide a useful guideline for optimization and safety evaluation of fittings.

A Method for Assessing the Thickness of Cobalt-Rich Crust on Seamounts and Its Application on the Il’ichev Guyot

Seamount cobalt-rich crusts are rich in cobalt resources and are sought after worldwide. Among different affecting parameters, crust thickness is the most important in evaluating cobalt-rich crust resources in seamounts. Generally, there are two challenges to crust thickness evaluation: firstly, due to high operating costs, most geological stations for seamount exploration have sparse sampling distributions so there are insufficient data to estimate the crust thickness distribution; secondly, a single evaluation method has advantages and disadvantages, and it is not feasible to benefit from the advantages only. These methods cannot simultaneously make full use of the sampling data in local areas, providing a more appropriate evaluation of the whole area. As a result, the estimated results cannot fully reflect the thickness distribution. Based on the thickness data of the station survey and topographic data, geostatistical units are divided, and a comprehensive crust thickness assessment scheme is established on the ArcGIS platform. To this end, the adjacent area method is applied to calculate the crust thickness within the influence range of the station. Combined with the station buffer radius and Thiessen polygon method, the crust thickness within 1.5 km of the survey station was estimated. Then the “slope–distance” Kriging interpolation method was used to calculate the crust thickness in the study area, and the crust thickness in the optimal effective radius area was given to compensate for the missing part in the first step. Finally, the geological blocks were divided using the topographic classification method, and the crust thickness of the remaining unassigned regions was estimated using the mathematical expectation method. The proposed method was applied to evaluate the Il’ichev Guyot’s crust thickness and reasonable results were achieved. It was found that the thickness estimation of the area near the station is consistent with the measured values. Since finer topographic data are used in the calculation, the thickness estimation result is more detailed. In this regard, a simple and effective calculation method was established on the ArcMap platform. The mathematical expectation estimation method of the crust thickness, based on the topographic and geomorphological classification from the perspective of the mineralization mechanism, compensates for the drawbacks of the first two methods originating from the lack of data points. The results show that the proposed method is an appropriate scheme to evaluate seamount crust thickness without comprehensive investigation.

Seasonal energy efficiency ratio of regenerative indirect evaporative coolers—Simplified calculation method

Evaporative-cooling technology is a promising alternative to conventional air-cooling systems that are based on using direct expansion units in terms of energy efficiency. Seasonal energy efficiency ratio (SEER) calculation methodologies and standards for these air-cooling systems remain limited. Therefore, the objective of this study is to develop a novel simplified method for calculating the SEER for regenerative indirect evaporative coolers (RIEC). Experimental tests were performed to obtain energy efficiency ratio models of four RIEC systems. Five climate zones in the Mediterranean region were considered for calculation of the SEER values. A detailed calculation method based on annual energy simulations was employed, and the results of the seasonal index were compared with those of a simplified calculation method based on the steady-state operation at four specific test points. The relative error between the SEER calculation methods was 4.6% for all the RIEC systems and climate zones. The highest SEER values of 5.8 and 5.5 were achieved for the Cairo and Madrid weather conditions, respectively. This study can serve as a reference for research on the seasonal performance and life-cycle analysis of RIEC based on an efficient counterflow heat exchanger with a wide range of airflow and cooling capacities.