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The study based on hydrogen-diesel co-direct injection system: A correction algorithm for circulating gas injection mass

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ENERGY 2025年 319卷

作者： Yang, Xiyu Yang, Fangliang Dong, Quan Shi, Cheng Li, Nan Zhang, Liang Yanshan Univ Sch Vehicle & Energy Qinhuangdao 066004 Peoples R China Yanshan Univ Hebei Engn Res Ctr Low Carbon Dev & Resource Utili Qinhuangdao 066004 Peoples R China Harbin Engn Univ Inst Power & Energy Engn Harbin 150001 Peoples R China

This study focuses on gas injection mass fluctuation in high-pressure hydrogen coupling direct injection technology for jet ignition, conducting research to optimize injection process stability. Investigating the fluctuation mechanism reveals that diesel pressure fluctuation induced by pilot injection is the fundamental cause for circulating gas injection mass fluctuation. It is found that the free diesel pressure oscillation within the fuel system and gas injection mass fluctuation at varying injection interval time both exhibit an under-damped oscillation pattern. In view of this, the research addresses stability optimization for gas injection mass from two aspects. On the one hand, the mechanism of the Helmholtz filter to reduce pressure fluctuation is explored in system structural aspect, and designed the structural parameters based on its resonant angular frequency. Then, the influence from different volumes on pressure fluctuation within the low-impedance region is analyzed. Through experimental verification, it is known that this method can reduce gas injection mass fluctuation, but it will decrease the total gas injection mass. On the other hand, an energizing time correction algorithm based on predictive model is proposed. By fitting and optimizing the each parameter sub-algorithms, the final corrected injection pulse width is obtained by combining the each parameter sub-algorithms. The results show that the Helmholtz filter can achieve a maximum reduction in gas injection mass fluctuation reaching 69.82 %. But compared with the original system, the total gas injection mass is reduced by about 7.4 %. The correction model can reduce the gas injection mass fluctuation reach up to 83.92 % and do not affect the total gas injection mass. The results can provide a theoretical basis for the advanced engine fuel injection process closed-loop control, and the experimental data can provide a reference for a dual-fuel injection system.

关键词： Dual-fuel injection Hydrogen Gas injection mass fluctuation Helmholtz filter correction algorithm

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correction algorithm for calculating heat transfer in air-cooling condenser based on analyzing steam condensation locations

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ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS 2023年第3期45卷 6744-6755页

作者： Li, Mingtao Wang, Zihao Liu, Chunxiao Meng, Xunbiao Zhang, Yan Shi, Jinwen Sun, Xinfeng Li, Gaochao Gao, Lixiao Liu, Duwei Shaanxi Yulin Energy Grp Hengshan Coal Elect Co Lt Prod Technol Dept Yulin Shaanxi Peoples R China Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn Xian Shaanxi Peoples R China Xian Thermal Power Res Inst Co Ltd Energy Conservat & Emiss Reduct Technol Ctr Xian Shaanxi Peoples R China Xi An Jiao Tong Univ State Key Lab Multiphase Flow Power Engn 28 Xianning West Rd Xian Shaanxi Peoples R China Xian Thermal Power Res Inst Co Ltd Energy Conservat & Emiss Reduct Technol Ctr Block ABoyuan Sci & Technol Plaza99Yanxiang Rd Xian Shaanxi Peoples R China

A correction algorithm based on analyzing the steam condensation locations is proposed to address the problem of large errors when calculating the heat transfer of the air-cooling condenser (ACC) in Fluent. By building a detailed geometric model of the ACC and using radiator boundary conditions to simplify the heat-sinking tube bundle, Fluent software was used to calculate the heat transfer of the ACC under four winter operating conditions, and then, the calculation results were further corrected by applying the correction algorithm. The results show that after using the correction algorithm, the errors between calculation results and experiment data are reduced from 4.20 similar to 36.98% to 0.01 similar to 1.79%. When the electric load of the air-cooling generator set or the ambient temperature was low, the condensation velocity increased, for which there would be a local steam-free area in the heat-sinking tube bundle of the ACC, leading to large errors when using the radiator model. At this point, the correction algorithm based on the analysis of steam condensation position can serve to improve the degree of accuracy. Meanwhile, this correction algorithm can be further expanded to use in the simulating calculation of an indirect air-cooling generator set, and it is able to correct the heat transfer calculation result of the air-cooling tower by analyzing the heat transfer condition of circulating water in the heat-sinking tube bundle, so that reliable data can be provided to guide the anti-freezing of the indirect air-cooling generator set.

关键词： Air-cooling condenser steam condensation location correction algorithm flow heat transfer calculation fluent

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correction algorithm for environmental scattering in industrial computed tomography

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NDT & E INTERNATIONAL 2014年 64卷 59-64页

作者： Schuetz, P. Jerjen, I. Hofmann, J. Plamondon, M. Flisch, A. Sennhauser, U. Empa Swiss Fed Labs Mat Sci & Technol CH-8600 Dubendorf Switzerland

Scattering of X-ray photons in the environment causes artefacts in high-energy X-ray computed tomography (CT). Here, an analytical correction formula applied to transmission images is presented and experimentally validated on data from a 450 kV cone-beam CT-system. This method increases the contrast of CT-images from a large aluminium step cylinder by a factor exceeding 2.5. For complex objects, the procedure reduces the variance of the attenuation values for the material given an optimal correction parameter. For the considered source parameters, this correction parameter could be derived from the measurement data by a simple procedure with a correlation coefficient of 0.996 +/- 0.005. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： X-ray scattering Environmental scattering correction algorithm Cone beam computed tomography

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correction algorithm based on fuzzy modeling for the distorted image in the digital X-ray scanner system

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JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2008年第1期16卷 9-22页

作者： Baek, Jaeho Park, Mignon Yonsei Univ Dept Elect & Elect Engn Seoul 120749 South Korea

The Digital X-ray Scanner System (DX-Scanner) using the Multichannel Ionization Chamber (MIC) has many advantages. On the other hand, the scanned medical image has distorted pixels because of unsuitable integration time at the nonlinear acceleration period and vibration of the AC servo motor during scanning a patient in the system. This paper proposes a correction algorithm based on fuzzy modeling. The proposed correction algorithm can correct the distorted medical image during scanning. Fuzzy modeling uses a clustering method for the nonlinear motor velocity in the algorithm. The algorithm reconstructs the normal medical image lines by calculating the moving distance every integration time during acceleration period of AC servo motor. The algorithm analyzes by comparing the distance of the acceleration period with the distance of the uniform velocity period in every integration time. The velocity for the acceleration period is able to be compensated via this algorithm. In addition, several image processing procedures are also included in the algorithm. When the proposed correction algorithm is applied to the test pattern for checking the image resolution, its effectiveness is verified at scanning of 3.5 cm/sec, 7 cm/sec, and 14 cm/sec. The corrected image is a better image.

关键词： digital X-ray radiography distorted image fuzzy modeling correction algorithm X-ray scanner Multichannel Ionization Chamber

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Scene-based nonuniformity correction algorithm based on interframe registration

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JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION 2011年第6期28卷 1164-1176页

作者： Zuo, Chao Chen, Qian Gu, Guohua Sui, Xiubao Nanjing Univ Sci & Technol Natl Def Key Lab Optoelect Engn Nanjing 210094 Jiangsu Prov Peoples R China

In this paper, we present a simple and effective scene-based nonuniformity correction (NUC) method for infrared focal plane arrays based on interframe registration. This method estimates the global translation between two adjacent frames and minimizes the mean square error between the two properly registered images to make any two detectors with the same scene produce the same output value. In this way, the accumulation of the registration error can be avoided and the NUC can be achieved. The advantages of the proposed algorithm lie in its low computational complexity and storage requirements and ability to capture temporal drifts in the nonuniformity parameters. The performance of the proposed technique is thoroughly studied with infrared image sequences with simulated nonuniformity and infrared imagery with real nonuniformity. It shows a significantly fast and reliable fixed-pattern noise reduction and obtains an effective frame-by-frame adaptive estimation of each detector's gain and offset. (C) 2011 Optical Society of America

关键词： interframe Noise reduction Focal plane arrays measuring datum error infrared imagery complexity classes adaptive estimation Mean square error NUCB1 gene correction algorithm Infrared imaging Storage requirements nonuniformity

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A dispersion and pulse width correction algorithm for the pulsed wire method

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NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 2013年 716卷 62-70页

作者： Arbelaez, D. Wilks, T. Madur, A. Prestemon, S. Marks, S. Schlueter, R. Univ Calif Berkeley Lawrence Berkeley Natl Lab Berkeley CA 94720 USA Univ Calif Berkeley Berkeley CA 94720 USA

The pulsed wire technique is an attractive option for the measurement of undulators where the measurement access is restricted due to, for example, narrow undulator gaps or cryogenic environments in the case of superconducting undulators. Using the pulsed wire technique, direct measurements of the first and second integrals of the magnetic field can be obtained. However, one of the main limitations of this technique is the error introduced by dispersive wave motion, due to the finite flexural rigidity of the wire. For the measurement of the first integral of the magnetic field, an error is also introduced by the use of a current pulse with finite pulse width. In this paper, a general solution is presented for dispersive wave motion in pulsed wire measurements. A method for the measurement of the dispersive wave speed is presented and demonstrated through experimental examples. An algorithm is derived which corrects the dispersion and finite pulse-width errors in the measurement of first magnetic field integrals and the dispersion error in the measurement of second magnetic field integrals. The effectiveness of the correction algorithms is demonstrated through experimental measurements, and the results are compared with Hall probe measurements on a short undulator. (c) 2013 Elsevier B.V. All rights reserved.

关键词： Pulsed wire Magnetic measurement Undulator Dispersion correction algorithm

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Co-located tipping-bucket and optical drop counter RI measurements and a simulated correction algorithm

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ATMOSPHERIC RESEARCH 2013年第Jan.期119卷 3-12页

作者： Colli, M. Lanza, L. G. Chan, P. W. Univ Genoa Dept Construct Environm & Architectural Engn I-16145 Genoa Italy Hong Kong Observ Honk Kong Peoples R China

A drop counter catching-type gauge and a tipping-bucket rain intensity gauge are compared in this paper in order to investigate the performance of suitable correction algorithms. Comparison in the field is performed at the resolution of 1 min by assuming the drop counter as a working reference at low to medium rainfall rates. The observed deviations are mainly the result of sampling errors due to the low resolution (0.5 mm) of the tipping-bucket. Two correction algorithms for this gauge are compared based on the knowledge of the time of tipping: since this is not actually available for the instrument in hand, numerical simulation is performed using information from the drop counter at the resolution of 10 s. The first correction is obtained by distributing the tip volume over the inter-tip periods. The second algorithm further applies a "smoothing" procedure that redistributes the volume of initial, isolated and final types of tips according to climatology. Relative deviations of the one-minute rainfall intensity figures are used to assess improvements in the observed measurement performance. Sensitivity of the results upon varying the sampling resolution of a virtual tipping-bucket rain gauge is also investigated using numerical simulation. It is concluded that the knowledge of the time of tipping is essential to improve the performance of the tipping-bucket rain gauge. Distributing the tip volume over the inter-tip period is indeed sufficient to considerably improve the measurement accuracy, especially at low to medium intensities and a fine sampling resolution. The influence of the correction at high rainfall intensity increases with decreasing sampling resolution. Although the proposed smoothing algorithm provides further improvements at low intensities for gauges characterized by coarse sampling resolution, where the first algorithm is less effective, the results are still affected by a significant spread of deviation. (C) 2011 Elsevier B.V. All rights reserved

关键词： Rainfall intensity Rain gauge Accuracy correction algorithm Drop counter Tipping-bucket

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Implementation of the near-field signal redundancy phase-aberration correction algorithm on two-dimensional arrays

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IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL 2007年第1期54卷 42-51页

作者： Li, Yue Robinson, Brent CSIRO Informat & Commun Technol Ctr Sydney NSW Australia Philips Ultrasound Bothell WA USA

Near-field signal-redundancy (NFSR) algorithms for phase-aberration correction have been proposed and experimentally tested for linear and phased one-dimensional arrays. In this paper the performance of an all-row-plus-two-column, two-dimensional algorithm has been analyzed and tested with simulated data sets. This algorithm applies the NFSR algorithm for one-dimensional arrays to all the rows as well as the first and last columns of the array. The results from the two column measurements are used to derive a linear term for each row measurement result. These linear terms then are incorporated into the row results to obtain a two-dimensional phase aberration profile. The ambiguity phase aberration profile, which is the difference between the true and the derived phase aberration profiles, of this algorithm is not linear. Two methods, a trial-and-error method and a diagonal-measurement method, are proposed to linearize the ambiguity profile. The performance of these algorithms is analyzed and tested with simulated data sets.

关键词： aberrations biomedical ultrasonics medical image processing diagonal-measurement method linear one-dimensional array medical ultrasound images near-field signal redundancy algorithms phased one-dimensional array simulated data set trial-and-error method correction algorithm biomedical ultrasonics Dataset Ultrasonography two-dimensional array algorithms simulated data TRIAL AND ERROR Medical image processing aberration near-field aberrations

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A correction algorithm of geometric unsharpness for neutron radiographs via adaptive fusion and total variation

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NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 2024年 1066卷

作者： Wu, Huajie Wang, Qihong Wu, Yifan Lyu, Yongqiang Gan, Quan Shi, Xueyan Wang, Wen Song, Jing Chinese Acad Sci Hefei Inst Phys Sci Hefei 230031 Peoples R China Univ Sci & Technol China Hefei 230026 Peoples R China SuperRay Technol Co Ltd Qingdao 266041 Peoples R China Int Acad Neutron Sci Qingdao 266199 Peoples R China Neutron Times Innovat Sci & Technol Co Ltd Qingdao 266043 Peoples R China Shandong Key Lab Neutron Sci & Technol Qingdao 266199 Peoples R China

The mobility of accelerator-based neutron sources has laid the foundation for the miniaturization of neutron radiography facilities in response to the increasing industrial requirements. Compared to traditional reactors and spallation neutron sources, miniaturized neutron radiography facilities based on accelerator neutron sources face challenges in achieving a sufficiently high collimation ratio. It leads to a pronounced level of geometric unsharpness on neutron radiographs, which arises from a finite source size and beam divergence. The presence of blurriness in radiographs significantly impairs the ability to accurately visualize the internal structures of the test objects, thus hindering observation. An algorithm combining adaptive fusion with total variation was proposed to correct the geometric unsharpness for neutron radiographs in this paper. In contrast to most traditional restoration algorithms that relied on regularization terms or filters, our proposed method offered both initial restoration and further restoration. The initial restoration procedure involved the utilization of the Richardson- Lucy algorithm coupled with the l 0 smoothing method. This adaptive fusion technique was employed to enhance the sharpness of edges and denoise the neutron radiographs. Finally, the result of the adaptive fusion was embedded into a deblurring model based on total variation to further preserve the edges and restore more details during further restoration. In the experiments, it was demonstrated that our correction algorithm effectively preserved the prominent edges and the details in both the simulated and real neutron radiographs of thin and thick objects, exhibiting fewer ringing effects than traditional algorithms. It is worth mentioning that our work is primarily applicable and significant to neutron generators, but not for reactors or spallation neutron sources that can deliver much better images.

关键词： Neutron radiograph Geometric unsharpness correction algorithm Image restoration

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An automatic atmospheric correction algorithm for visible/NIR imagery

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INTERNATIONAL JOURNAL OF REMOTE SENSING 2006年第9-10期27卷 2077-2085页

作者： Richter, R Schläpfer, D Müller, A DLR German Aerosp Ctr Remote Sensing Data Ctr D-82234 Wessling Germany Univ Zurich Remote Sensing Labs CH-8057 Zurich Switzerland

The automatic correction of atmospheric effects currently requires visible to short-wave spectral bands (400-2500 nm) to derive high accuracy surface reflectance data. Common techniques employ spectral correlations of dark targets in the short-wave infrared (SWIR, around 2.2 mu m), blue (480 nm) and red (660nm) regions to derive the aerosol optical depth. A large number of current Earth-observing satellite sensors have only three or four spectral channels in the visible and near-infrared (VNIR) region (400-1000 nm), making an automatic image-based atmospheric correction very difficult. This contribution presents a new algorithm and first results with VNIR imagery. The method starts with the assumption of average clear atmospheric conditions (aerosol optical depth AOD=0.27, corresponding to a visibility of 23km) and calculates the surface reflectance in the red and near-infrared (NIR) bands. The second step derives a mask of dark vegetation pixels. It is calculated using multiple thresholds of vegetation index combined with red and NIR surface reflectance values. Then the red band surface reflectance for the dark pixels is estimated from the NIR reflectance as rho(red)=0.1 rho(nir), from which the aerosol optical depth (or visibility) can be calculated. The core of the VNIR algorithm consists of two subsequent iteration loops (visibility and Pred) to improve the visibility estimate. Results of the VNIR method are presented for Landsat-5 Thematic Mapper (TM) and Landsat-7 Enhanced Thematic Mapper Plus (ETM +) imagery using only the first four bands. The performance of the method is compared to the established dark pixel technique where the SWIR bands are included. Results show that the deviation between both methods is usually less than 0.005 reflectance units if measured in terms of the scene-average reflectance, indicating a useful potential for this approach.

关键词： Vegetation Index surface reflectance atmospheric correction thematic mapper correction algorithm VNIR visibility optical thickness

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