Loss Coefficient Research Articles

DESIGNATION OF THE HEAD LOSS COEFFICIENT IN FITTINGS CFD

The optimization of pumping systems is important because it leads to an increment of improved energy efficiency. This study analyzes the hydraulic behavior of clean water through pressurized fittings which is analyzed numerically. The numerical experiment is carried out using Ansys Fluent software. The flow characterization through the fittings was performed using the coefficient of minor losses (KL). Two short radius elbows of 45° and 90°, and a PVC tee (simple) were used. The procedure used for the development of the numerical experimentation in this study is as follows: geometry construction, discretization, boundary conditions, configuration of the numerical simulation parameters, validation, CFD parametric study, and the analysis of results. The results of the flow simulation on the meshes showed a high sensitivity to the mesh size. To determine the optimal element size, a mesh independence study was performed, which consisted of refining the mesh to stable values. The numerical results were compared with values calculated using conventional equations for minor losses in the fittings. The KL values were characterized by two methods: in the first one the behavior of KL with respect to Reynolds number in turbulent flow was studied, in the second one the relative percentage of loss error was determined in comparison with previous investigations on this subject. The numerical results showed an acceptable relative error for the three simulated fittings.

Effects of curved vanes on aerodynamic performance and flow structures in highly loaded tandem cascades

Combining tandem cascades and curved vanes can mitigate the separation in highly loaded compressor cascades. Flow loss mechanisms in curved tandem cascades are crucial for fundamental design and optimization. This study investigates the flow losses and vortex structures in curved tandem cascades with different curved angles and an original straight tandem cascade. Numerical simulations are conducted at variable incidence angles. The results indicate no consistent effect of curved angles on the aerodynamic performance of curved tandem cascades. The tandem cascade with a curved angle of 5° effectively reduces losses at all incidence angles, while the tandem cascade with a curved angle of 15° extends the critical incidence angle to 3°. The comparative analyses reveal that curved vanes increase spanwise pressure gradients, causing low-energy fluid near endwalls to move toward the midspan. The weighting coefficient of losses quantitatively describes that curved vanes weaken the trailing edge shedding vortices of both vanes and passage vortex while enhancing the end wall spanwise vortex of the front vane, thus affecting the loss distribution. Finally, this study innovatively applies topological analysis methods to curved tandem cascades, establishing the relationship between topological structures and vortex structures in corner regions of tandem cascades, which provides a valid research approach to reveal the vortex dynamics mechanisms of the loss distribution in tandem cascades influenced by curved vanes.

Extraction of geometric features and analysis of flow mechanism of high loaded compressor airfoils at low Reynolds number

When the aircraft cruising at high altitude, the aerodynamic performance of the compressor sharply decreases due to the enhanced boundary layer separation loss. Therefore, it is of great significance to design the high-performance airfoils suitable for low Reynolds numbers (Re) to improve the aerodynamic performance of compressor. In this paper, numerical simulations were carried out on a high-loaded subsonic compressor cascade V103 at low Re. Meanwhile, a multi-objective optimization of blade profile was performed to get optimal solutions, and data mining techniques were applied to extract valuable design knowledge from the optimal database. The results show that the Pareto-optimal airfoils achieve a maximum reduction of 27.32% in total pressure loss coefficient under design condition and 36.71% under near stall condition. Compared with the original airfoil, the curvature distribution law of the camber line with larger values at both ends and smaller values in the middle is advantageous for the performance of the compressor cascade under design condition. This distribution pattern causes a forward shift for the loading distribution of airfoils, accompanied by an earlier transition onset. Additionally, it reduces adverse pressure gradient at the rear part of suction surface, which suppresses the development and growth of laminar separation bubble and delays the separation of turbulent boundary layer. Under near stall condition, maintaining larger leading edge angle and uniform flow diffusion is beneficial for improving the performance of compressor cascade. This is because the larger leading edge angle reduces incidence angle, while the uniform flow diffusion inhibits a great flow separation.

Effects of the geometrical parameters on rectification characteristics of convergence angle throttle orifice plates

Under severe operating conditions, the conventional porous plates are rendered ineffective in rectifying the spiral turbulence generated during the steam flow and pressure adjustment process by the primary pressure-reducing valve (PPRV). To address this limitation, an innovative throttle plate with a convergent angle structure is proposed based on the conventional uniformly distributed porous plate in this study. The design aims to rectify the spiral turbulence generated after PPRV and elucidate its formation mechanism. However, there is currently no clear understanding or reliable prediction method for the pressure loss coefficient due to various structural factors influencing the rectification characteristics and pressure drop properties of the converging angle structure throttle orifice plate. This lack of knowledge severely hampers practical applications of this new plate in pressure-reducing desuperheating devices. To address this issue, the present study investigates the underlying mechanisms governing the rectification characteristics and flow resistance properties of a throttle orifice plate with a converging angle structure through experimental investigations and numerical simulations. The focus is on geometric parameters including the converging angle (θ), orifice diameter (d), throttle diameter ratio (β), and plate thickness (h). The findings suggest that the incorporation of a converging angle structure throttle orifice plate is advantageous in achieving effective rectification of spiral turbulence in the secondary pressure pipeline of the pressure-reducing desuperheating device. This modification reduces the required channel distance for enhancing unstable flow, diminishes velocity non-uniformity, and augments the rectification and control capabilities of the medium.

Local strain quantification of a porous carbon fiber network material

While porous materials’ wide range of attractive functional properties have led to their development for a variety of applications, their intrinsically stochastic microstructures prevent straightforward approaches to predicting their mechanical behavior. This is attributed to the mechanisms that govern the macroscale behavior of these materials operating on multiple microstructure-specific length scales spanning several orders of magnitude. The goal of this work was to experimentally observe these operative deformation mechanisms to better improve the development of mechanism-informed models that more accurately predict the behavior of these materials. In this study compression tests were conducted on a porous carbon fiber network material. The resulting macroscale mechanical properties and mesoscale deformation behavior were tied together through digital image correlation (DIC) strain mapping. It was shown that deformation accumulation occurred via both reversible (fiber bending and sliding) and irreversible (fiber and junction failure) ways. The presence of irreversible deformation is indicated by strain being retained after unloading, with values of up to 0.426 locally and 0.248 globally. Local and macroscopic recovery of up to 0.306 and 0.207 strain respectively showcase the operation of reversible deformation. Furthermore, the calculation of energy loss coefficients increasing from 0.016 to 0.371 illustrates that the deformation occurs via dissipative mechanisms.

Mechanisms of Characteristic Parameters of Plasma Actuator on Film Cooling and Turbulent Transport Based on Multi-Objective Optimization

In this paper, film cooling effectiveness and pressure loss coefficient are taken as the objective functions to optimize the plasma characteristic parameters such as electrode position, spacing, length and actuation intensity for enhancing film cooling performance. Regression equations of two objective functions are accessed by the Response Surface Method, and Non-Dominated Sorting Genetic Algorithm is applied for bi-objective optimization. Two sets of Pareto optimal solutions are available via the Technique for Order Preference by Similarity to an Ideal Solution decision method. Pareto optimal solutions are calculated by Detached Eddy Simulation to clarify the turbulent transport and heat transfer characteristics induced by the plasma. Wall-averaged cooling effectiveness and pressure loss coefficient without plasma power supply are 64.3% and 3.9% superior to that without electrode, respectively. The plasma fragments the hairpin vortex into a striped structure and induces a large scale streamwise vortex behind the bare electrode. The plasma weakens the velocity diffusion and turbulent heat transport in the ionization zone. Overlapping electrodes render the root-mean-square pulsation velocity and Reynolds stress of the optimal model 1 both less than those of the optimal model 2 without overlapping electrodes, and flow field disorder is decreased. Electrode position interferes with the action location of plasma on cooling jet. Actuation intensity affects the ionization intensity and has a maximum value of 8.88 to optimize the actuator performance. Compared with no plasma actuation, wall-averaged cooling effectiveness of optimal model 1 and optimal model 2 are enhanced by 30.7% and 21.8%, and pressure loss coefficient are declined by 7.7% and 7.1%, respectively.

Analysis of upper and lower nappe profiles of large orifice for the design of bottom and roof profiles of high head orifice spillway

Abstract Large orifices are constructed for dams to release water and sediments from reservoirs. Such structures are called submerged spillways. Numerous studies have investigated discharge coefficient, velocity coefficient, and head loss coefficient of large orifices; however, the literature lacks data on the upper and lower nappes of the jets from these orifices. In the present experimental study, the upper and lower nappes are investigated up to 80 m head at different gate openings. The observed minor deviation between the lower nappe profile and trajectory profile equation suggests sensitivity to different factors. The significant role of the coefficient of velocity, averaging at 0.926, highlights its impact on minor deviation. Subsequently, the impact of the solid bottom profile on the discharge coefficient and upper nappe profile are also examined. The results show improvement in discharge coefficient of a sharp-edged large orifice, which increased from 0.69 to 0.74. The results also indicate that the upper nappe profiles and United States Bureau of Reclamation (USBR) profiles are similar. The improvement in the upper nappe profile indicates the significant role of the solid bottom profile, which consequently was found to be helpful in defining the roof profile of an orifice spillway. .

Investigation on the pressure drop characteristics of ITER thermal shield cooling pipes

This paper presents the experimental results of the pressure drop through the cooling pipes of the ITER Thermal Shield (TS) panels. High pressure and room temperature nitrogen gas is selected for the experiment, which is equivalent operating condition with the 80 K helium gas from fluid mechanics point of view. Flow rate is set by a mass flow controller and pressure difference between the inlet and the outlet of the cooling pipe is measured by a differential pressure gauge. The experimental set-up is open loop type, which is connected to high pressure gas bottle. Flexible corrugated pipes are used to connect the TS cooling pipes with the measurement system line. The effect of the corrugated pipe is evaluated separately and excluded from the measurement results of the TS pipes. Test results of several TS panels are shown in this paper and are compared with the calculation using existing friction factor correlation and local loss coefficient of the pipe bends. The limitation of the calculation is discussed considering the hydrodynamic developing flow in the pipe routing.

Analysis of Flow Instability and Mechanical Energy Loss of Fluid Field in Fluid Momentum Wheel

A new type of anti-rolling device denoted as a fluid momentum wheel (FMW) is proposed to address the limitations of traditional gyrostabilizers in reducing the roll responses of floating platforms in waves. The proposed device is based on the same gyroscope theorem, which differs from a rigid gyrostabilizer in that the internal fluid generates secondary flow in the cross-section under the combined effects of inertial centrifugal force and a radial pressure gradient, and the streamwise velocity exhibits a non-uniform distribution. These instability phenomena may cause mechanical energy loss in the flow field, which is critical for selecting the driving device and the anti-roll control performance of offshore platforms. In the study, different turbulence models are compared with the results of a Direct Numerical Simulation (DNS) and experiments to ensure the accuracy of the numerical method, and the spatiotemporal distribution characteristics of the flow field in FMW are analyzed. Therein, the SST k-ω model accurately verifies the flow instability phenomenon of the FMW observed in the Particle Image Velocimetry (PIV) experiment. Next, this paper proposes corresponding evaluation parameters to assess the impact of typical parameters on the flow field instability. The results show that the flow instability increases with an increase in the typical parameters of FMWs (such as the pipe diameter, curvature radius, and velocity). Furthermore, the paper discusses the relationship between dimensionless mechanical factors (Reynolds number, curvature ratio) and the spatiotemporal instability of the flow field, revealing the essential effects of the curvature ratio and Reynolds number on the loss coefficient.

Colossal permittivity and low dielectric loss of Ta5+ and Al3+ co-doped strontium titanate ceramics sintered in N2 atmosphere

In this work, the ceramics of Sr(Ta1/2Al1/2)xTi1-xO3 (x = 0 %, 0.5 %, 1 %, 2 %, 3 %, 4 %, and 5 %) were produced through the solid-state reaction and sintered under N2 atmosphere. The frequency coefficient of permittivity and dielectric loss for the sample with x = 4 % is blow |24%| and |26%|, respectively, within the frequency of 1 kHz to 1 MHz. This demonstrates favorable frequency stability in the dielectric properties. The sample with x = 4 % exhibits remarkable permittivity (εr ∼ 125,000 @ 1 kHz, εr ∼ 95,000 @ 1 MHz) and low dielectric loss (tanδ ∼ 0.054 @ 1 kHz, tanδ ∼ 0.044 @ 1 MHz) were achieved at room temperature. Through the analysis of HAADF-STEM, XPS, it is concluded that and dielectric relaxation, the colossal permittivity effect is primarily attributed to defect clusters associated with oxygen vacancies such as Ti3+−VO••− Ti3+. The clusters of defect dipoles exert a pinning effect on freedom electrons, constraining their long-range transition and improving the dielectric properties. This study lays the foundation for advancing the electronic components, making a significant milestone in technological advancements.

Fretting wear characteristics of Ti6Al4V/TiC nano composites using response surface method

This study explores the impact of titanium carbide (TiC) nanoparticles on the microstructure and fretting wear performance of Ti64-GV alloys. The Ti64 alloys, featuring varying TiC concentrations, were fabricated through spark plasma sintering (SPS) process. Fretting experiments followed a face-centered central composite design methodology, employing a second-order quadratic regression model to analyze wear volume loss and coefficient of friction (CoF). The findings revealed a notable reduction in wear volume loss and friction coefficient with increasing TiC content. The presence of TiC significantly enhanced the wear resistance of Nano-composites due to heightened hardness and oxidation wear resistance. Employing hybrid desirability-based response surface methodology (RSM) led to substantial improvements in wear characteristics (37% in CoF and 46% in wear volume loss). Microstructural analysis affirmed enhanced surface quality and textures using the RSM hybrid approach for predicting optimal process parameters.

Effect of Oxidation Process on Mechanical and Tribological Behaviour of Titanium Grade 5 Alloy.

In this study, microstructural characterization, mechanical (tensile and compressive) properties, and tribological (wear) properties of Titanium Grade 5 alloy after the oxidation process were examined. While it is observed that the grey contrast coloured α grains are coaxial in the microstructures, it is seen that there are black contrast coloured β grains at the grain boundaries. However, in oxidised Titanium Grade 5, it is possible to observe that the α structure becomes larger, and the number and density of the structure increases. Small-sized structures can be seen inside the growing α particles and on the β particles. These structures are predicted to be Al-Ti/Al-V secondary phases. The nonoxidised alloy matrix and the OL layer exhibited a macrolevel hardness of 335 ± 3.21 HB and 353 ± 1.62 HB, respectively. The heat treatment increased Vickers microhardness by 13% in polished and etched nonoxidised and oxidised alloys, from 309 ± 2.08 HV1 to 352 ± 1.43 HV1. The Vickers microhardness value of the oxidised sample was 528 ± 1.74 HV1, as a 50% increase was noted. According to their tensile properties, oxidised alloys showed a better result compared to nonoxidised alloys. While the peak stress in the oxidised alloy was 1028.40 MPa, in the nonoxidised alloy, this value was 1027.20 MPa. It is seen that the peak stresses of both materials are close to each other, and the result of the oxidised alloy is slightly better. When we look at the breaking strain to characterise the deformation behaviour in the materials, it is 0.084 mm/mm in the oxidised alloy; In the nonoxidised alloy, it is 0.066 mm/mm. When we look at the stress at offset yield of the two alloys, it is 694.56 MPa in the oxidised alloy; it was found to be 674.092 MPa in the nonoxidised alloy. According to their compressive test properties, the maximum compressive strength is 2164.32 MPa in the oxidised alloy; in the nonoxidised alloy, it is 1531.52 MPa. While the yield strength is 972.50 MPa in oxidised Titanium Grade 5, it was found to be 934.16 MPa in nonoxidised Titanium Grade 5. When the compressive deformation oxidised alloy is 100.01%, in the nonoxidised alloy, it is 68.50%. According to their tribological properties, the oxidised alloy provided the least weight loss after 10,000 m and had the best wear resistance. This material's weight loss and wear coefficient at the end of 10,000 m are 0.127 ± 0.0002 g and (63.45 ± 0.15) × 10-8 g/Nm, respectively. The highest weight loss and worst wear resistance have been observed in the nonoxidised alloy. The weight loss and wear coefficients at the end of 10,000 m are 0.140 ± 0.0003 g and (69.75 ± 0.09) × 10-8 g/Nm, respectively. The oxidation process has been shown to improve the tribological properties of Titanium Grade 5 alloy.

A data-driven polynomial chaos method for uncertainty quantification of a subsonic compressor cascade with stagger angle errors

The probability-based uncertainty quantification (UQ) methods require a large amount of sampled data to construct the probability distribution of uncertain input parameters. However, it is a common situation that only limited and scarce sampled data are available in engineering applications due to expensive tests. In the present paper, the Data-Driven Polynomial Chaos (DDPC) method is adopted, which can propagate input uncertainty in the case of scarce sampled data. The calculation accuracy and convergence of the self-developed DDPC method are validated by a nonlinear test function. Subsequently, the DDPC method is applied to investigate the uncertain impact of stagger angle errors on the aerodynamic performance of a subsonic compressor cascade. A family of manufacturing error data of stagger angles was obtained from the real compressor blades. Based on the limited measurement data, the DDPC method combined with Computational Fluid Dynamics (CFD) simulation is employed to quantify the performance impact of the compressor cascade. The results show that the performance dispersion under off-design conditions is more prominent than that under design conditions. The actual aerodynamic performance deviating from the nominal performance is not a small probability event, and the probability of deviating from the nominal loss coefficient and exit flow angle by more than 1% can reach up to 47.6% and 36.8% under high incidence i = 7°. Detailed analysis shows that stagger angle errors have a significant effect on the flow state near the leading edge, resulting in variations in separation bubble size and boundary layer thickness.

Solar Hybrid System: Innovations in Cooking, Drying, and Power Generation

A hybrid system has been designed and developed which comprises the principle of solar thermal and photovoltaic. Flat plate collector and concentrating trough collector were incorporated under solar thermal technology. Solar thermal device which makes the most using infrared radiation out of solar spectrum. Black copper sheet at focal point of the solar trough served as a stand for cooking pan was able to gain direct as well as high intensity reflected solar radiation to expedite the cooking process. The electric unit of the system worked on the principle of photovoltaic effect. Main components of the hybrid system were collector housing, solar trough reflector, triangular shaped glazing surfaces, copper sheet to place cooking pots and dedicated insulation to prevent heat loss. The dual concept hybrid system was found exceptionally speedier as compared to traditional box type cooker. Results revealed that cooking pot attained maximum temperature of 104.50 C at 12.30 pm, which was sufficient for cooking nutritious food. The experiment was conducted in winter season on 18th January, 2018. Average thermal efficiency (ηtherm) was estimated as 35.1%, cooking power (P) was estimated 47.68 W and the overall heat loss coefficient was calculated 3.03 W/m2°C. Average cooking time found to be just 130 minutes which was otherwise more than 3 hrs in case of traditional box type cooker. Electric power which was stored in the battery can operate 5W dc bulb for 9 hours in single charging. It also could operate smart phone charger and a dc fan (12V, 4Ah) for 60 minutes each.

Tribological and impact- toughness performance of friction stir processed AA7075

This technical investigation used friction stir processing to modify the AA7075- T6 alloy and aimed to analyze the wear and impact toughness properties of the modified surfaces. Effects of the input parameters of the friction stir process (FSP) were also studied. Initially, the as-received AA-7075 alloy was processed using FSP at the selected parameters to get defect-free processed specimens. Next, the microstructures of the base alloy and processed regions were examined through an optical microscope. Then, the impact toughness was measured using the Charpy test, and sliding wear behavior was evaluated on a pin-on-disc tribo-tester. The processed samples’ average impact energy was better than the base material’s. Also, their wear property, i.e., coefficient of friction and weight loss, were more promising than the parent metal. Finally, fractography of the fractured Charpy test sampleswas done to study the fracture behavior; andSEM micrographs and 2D profiles of wear tracks were analysed to examine the wear behaviour properly.

Characteristics of the electromagnetic wave propagation in magnetized plasma sheath and practical method for blackout mitigation

“Magnetic window” is considered as an effective method to solve the communication blackout issue. COMSOL software package based on the finite element method is utilized to simulate the propagation of right-handed circularly polarized wave in the magnetized plasma sheath. We assume a double Gaussian model of electron density and an exponential attenuation model of magnetic field. The propagation characteristics of right-handed circularly polarized wave are analyzed by the observation of the reflected, transmitted and loss coefficient. The numerical results show that the propagation of right-handed circularly polarized wave in the magnetized plasma sheath varies for different incident angles, collision frequencies, non-uniform magnetic fields and non-uniform plasma densities. We notice that reducing the wave frequency can meet the propagation conditions of whistle mode in the weak magnetized plasma sheath. And the transmittance of whistle mode is less affected by the variation of the electron density and the collision frequency. It can be used as a communication window.

CFD verification of total pressure loss coefficient for gas-liquid two-phase flow

Traditionally, we design gas-liquid two-phase flow systems with pressure loss that is assumed by homogeneous flow. However, in real phenomena, the flow rate of water or air through a system cannot be correctly predicted unless we evaluate by the total pressure loss. there are currently few methods for measuring total pressure loss, and the value of total pressure loss is not yet clearly. Therefore, we devised a method to measure total pressure loss by pump Q-H characteristic and succeeded in measuring total pressure loss indirectly. We compared the test results with the analysis to clarify the prediction accuracy of the analysis using commercial codes. We apply three two-phase flow models for the simulation: a VOF model, a homogeneous flow model, and a two-fluid model. The simulation results of comparison between each fluid model indicated that the VOF model predicted with the best accuracy, with the error of 46% compared to the test results. This study provides a benchmark for the current commercial code, and the prediction accuracy of the different models provides a direction for future improvements in the analysis.

Evaluation of Loss Coefficient For Stand Alone Radiator

In the UK, domestic heating contributes to about 40% of annual energy consumption. Effective and efficient heating systems are essential to drive the cost of heating down. Although there are several types of heating systems, radiators are the most popular heat emitters. Head loss in a radiator depends on various design parameters based on fluid flow path conditions and design of the radiator. The work presented in this paper identifies and compares the loss co-efficient for two most common configurations of radiators used in domestic heating systems. These are Bottom-Bottom Opposite Ends (BBOE) and Bottom-Top Opposite Ends (BTOE) configurations for a standalone system. In a standalone radiator design the loss co-efficient K value varies with the panel configuration and flow path in the BBOE and BTOE layouts. Similar to loss co-efficient in a pipe system the K value in a radiator system is a function of the Reynolds number. It has been found that double and single panel radiators have significantly different behaviour for the two flow layouts with higher K values for the BTOE configuration at lower velocity.

Numeric simulation and experimental validation for a Novel Trapezoidal Solar Collector

In a global warming context, the diversification of the energy matrix is essential for mitigation. Technologies and solar devices have begun to play an important role in this sense, being flat-plate solar collectors the most practical device. On the other hand, numerical modeling and experimental validation are important tools for improving the performance of these technologies. In this work, a trapezoidal solar air heating collector for food drying processes was modeled by using the Simusol open-access software, and experimental validation was performed. This particular shape presents a geometrical novelty since no other similar designs were found into the available literature, even in such application as food drying. Key parameters, such as air temperature, global efficiency, air mass flow, global heat loss coefficient, and useful heat, are determined and discussed. The proposed air collector numerically behaves as expected. The output air temperature reaches about 100 °C, while the peak heat gain is about 900 W, which makes the air heating collector suitable for drying applications. Due to natural convection is the main heat transferring mechanism, low air mass flows were obtained. For the case analyzed here, this last parameter ranges in 0.012–0.016 kg/s for the optimal thermal behavior.

Unveiling the potential of concentric tubular solar stills (CTSS) through comprehensive thermodynamic modeling and analysis

ABSTRACT The present research work delves into the thermodynamic modeling and analysis of concentric tubular solar stills (CTSS) using a rigorous mathematical approach. The primary objective is to gain a comprehensive understanding of the system’s behavior by formulating and analyzing various crucial parameters. These parameters include the basin water temperature, inner and outer glass cover temperatures, heat transfer coefficients, heat loss coefficients, thermal efficiency, exergy efficiency, hourly yield, and cumulative yield. The study is specifically conducted under the environmental conditions of Nagpur city (21.1458° N, 79.0882° E), India, in the month of May 2022. By selecting this location, the present study ensures that their findings are contextually relevant and applicable to the local conditions. To facilitate the computation of results and generate informative visualizations, MATLAB code has been developed. This code allows for efficient analysis, processing, and presentation of the obtained data, enabling a comprehensive interpretation of the research findings. Results of the study indicate that hourly yield, considering only bottom losses, is 5.071 k g / m 2 and 3.012 k g / m 2 when water and air are used as cooling mediums, respectively. However, when all losses are taken into account, the hourly yield decreases to 4.575 k g / m 2 and 2.555 k g / m 2 for water and air as cooling mediums, respectively. The percentage error when water and air are used as the cooling medium by considering bottom losses is 1.05 and 3.06, while considering all losses, the error is 10.73 and 18.26.