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Article
Publication date: 7 October 2019

Qingxian Jia, Huayi Li, Xueqin Chen and Yingchun Zhang

The purpose of this paper is to achieve fault reconstruction for reaction wheels in spacecraft attitude control systems (ACSs) subject to space disturbance torques.

Abstract

Purpose

The purpose of this paper is to achieve fault reconstruction for reaction wheels in spacecraft attitude control systems (ACSs) subject to space disturbance torques.

Design/methodology/approach

Considering the influence of rotating reaction wheels on spacecraft attitude dynamics, a novel non-linear learning observer is suggested to robustly reconstruct the loss of reaction wheel effectiveness faults, and its stability is proven using Lyapunov’s indirect method. Further, an extension of the proposed approach to bias faults reconstruction for reaction wheels in spacecraft ACSs is performed.

Findings

The numerical example and simulation demonstrate the effectiveness of the proposed fault-reconstructing methods.

Practical implications

This paper includes implications for the development of reliability and survivability of on-orbit spacecrafts.

Originality/value

This paper proposes a novel non-linear learning observer-based reaction wheels fault reconstruction for spacecraft ACSs.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 10
Type: Research Article
ISSN: 1748-8842

Keywords

Open Access
Article
Publication date: 21 January 2022

Yong Li, Yingchun Zhang, Gongnan Xie and Bengt Ake Sunden

This paper aims to comprehensively clarify the research status of thermal transport of supercritical aviation kerosene, with particular interests in the effect of cracking…

Abstract

Purpose

This paper aims to comprehensively clarify the research status of thermal transport of supercritical aviation kerosene, with particular interests in the effect of cracking on heat transfer.

Design/methodology/approach

A brief review of current research on supercritical aviation kerosene is presented in views of the surrogate model of hydrocarbon fuels, chemical cracking mechanism of hydrocarbon fuels, thermo-physical properties of hydrocarbon fuels, turbulence models, flow characteristics and thermal performances, which indicates that more efforts need to be directed into these topics. Therefore, supercritical thermal transport of n-decane is then computationally investigated in the condition of thermal pyrolysis, while the ASPEN HYSYS gives the properties of n-decane and pyrolysis products. In addition, the one-step chemical cracking mechanism and SST k-ω turbulence model are applied with relatively high precision.

Findings

The existing surrogate models of aviation kerosene are limited to a specific scope of application and their thermo-physical properties deviate from the experimental data. The turbulence models used to implement numerical simulation should be studied to further improve the prediction accuracy. The thermal-induced acceleration is driven by the drastic density change, which is caused by the production of small molecules. The wall temperature of the combustion chamber can be effectively reduced by this behavior, i.e. the phenomenon of heat transfer deterioration can be attenuated or suppressed by thermal pyrolysis.

Originality/value

The issues in numerical studies of supercritical aviation kerosene are clearly revealed, and the conjugation mechanism between thermal pyrolysis and convective heat transfer is initially presented.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 32 no. 9
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 7 June 2019

Yingchun Zhang, Nesrin Ozalp and Gongnan Xie

The purpose of this paper is to investigate the unsteady flow past through a permeable diamond-shaped cylinder and to study the effects of the aspect ratios and Darcy…

167

Abstract

Purpose

The purpose of this paper is to investigate the unsteady flow past through a permeable diamond-shaped cylinder and to study the effects of the aspect ratios and Darcy numbers of the cylinder.

Design/methodology/approach

The lattice Boltzmann method with D2Q9 lattice model was used to simulate the unsteady flow through permeable diamond-shaped cylinders. The present numerical method is validated against the available data.

Findings

The key findings are that increasing the permeability enhances the suppression of vortex shedding, and that the Strouhal number is directly proportion to the Darcy number, Reynolds number and the aspect ratio of the porous cylinder.

Originality/value

The present study considers unsteady laminar flow past through single permeable diamond-shaped cylinder. According to the authors’ knowledge, very few studies have been found in this field. The present findings are novel and original, which in turn can attract wide attention and citations.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 9
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 18 July 2018

Bing Hua, Zhiwen Zhang, Yunhua Wu and Zhiming Chen

The geomagnetic field vector is a function of the satellite’s position. The position and speed of the satellite can be determined by comparing the geomagnetic field vector…

Abstract

Purpose

The geomagnetic field vector is a function of the satellite’s position. The position and speed of the satellite can be determined by comparing the geomagnetic field vector measured by on board three-axis magnetometer with the standard value of the international geomagnetic field. The geomagnetic model has the disadvantages of uncertainty, low precision and long-term variability. Therefore, accuracy of autonomous navigation using the magnetometer is low. The purpose of this paper is to use the geomagnetic and sunlight information fusion algorithm to improve the orbit accuracy.

Design/methodology/approach

In this paper, an autonomous navigation method for low earth orbit satellite is studied by fusing geomagnetic and solar energy information. The algorithm selects the cosine value of the angle between the solar light vector and the geomagnetic vector, and the geomagnetic field intensity as observation. The Adaptive Unscented Kalman Filter (AUKF) filter is used to estimate the speed and position of the satellite, and the simulation research is carried out. This paper also made the same study using the UKF filter for comparison with the AUKF filter.

Findings

The algorithm of adding the sun direction vector information improves the positioning accuracy compared with the simple geomagnetic navigation, and the convergence and stability of the filter are better. The navigation error does not accumulate with time and has engineering application value. It also can be seen that AUKF filtering accuracy is better than UKF filtering accuracy.

Research limitations/implications

Geomagnetic navigation is greatly affected by the accuracy of magnetometer. This paper does not consider the spacecraft’s environmental interference with magnetic sensors.

Practical implications

Magnetometers and solar sensors are common sensors for micro-satellites. Near-Earth satellite orbit has abundant geomagnetic field resources. Therefore, the algorithm will have higher engineering significance in the practical application of low orbit micro-satellites orbit determination.

Originality/value

This paper introduces a satellite autonomous navigation algorithm. The AUKF geomagnetic filter algorithm using sunlight information can obviously improve the navigation accuracy and meet the basic requirements of low orbit small satellite orbit determination.

Details

International Journal of Intelligent Computing and Cybernetics, vol. 11 no. 4
Type: Research Article
ISSN: 1756-378X

Keywords

Article
Publication date: 3 May 2016

Baolian Zhang, Zhenzhen Zhang, Xuening Fei, Yingchun Gu and Lu Yu

The purpose of the study reported in this paper was to prepare modified C.I. Pigment Red (PR) 170 to reduce production cost and improve application performance. The…

Abstract

Purpose

The purpose of the study reported in this paper was to prepare modified C.I. Pigment Red (PR) 170 to reduce production cost and improve application performance. The structure of the modified pigment was characterised. The colour strength, thermal stability, mobility, aqueous dispersability and ultraviolet (UV) resistance of modified pigments were studied.

Design/methodology/approach

Silica fume was added into the diazonium salt solution under acidic condition, followed by the activation to generate new surface. Subsequently, coupling component was dropwise added to the system to form the modified pigments evenly on the surface of silica fume in situ. The structure and properties of the modified pigment were studied by fourier transform infrared spectoscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermal gravity analysis (TG-DTA), UV-visible diffuse reflectance spectra (UV-Vis DRS), and commission internationale de L‘Eclairage (CIE L*a*b*) colour measurements.

Findings

The morphology and particle size of the modified pigment were controlled by the modification of the silica fume, and the organic pigment and silica fume formed a core–shell structure. The properties of the modified pigment including colour strength, thermal stability, mobility, aqueous dispensability and UV resistance were improved significantly.

Research limitations/implications

The effect of the amount of silica fume on the thickness of the organic pigment layer and the effect of the thickness of the organic pigment layer on the properties of the modified pigment need to be studied further.

Practical implications

This paper shows a feasible method of the modification of the PR170 with the silica fume, and the modification can improve the properties of the PR170. The use of silica fume to modify organic pigment can realise the reuse of solid waste and reduce the production cost of the organic pigment.

Social implications

This modification method of the organic pigment is adaptive and it can be adjusted to the modification of other species of the organic pigment.

Originality/value

The modification of the PR170 with the silica fume was carried out in its preparation process, which synchronised the preparation and modification of the organic pigment. The properties of the modified pigment were improved, which were beneficial for their application in inks and coatings.

Details

Pigment & Resin Technology, vol. 45 no. 3
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 2 December 2021

Seyhun Durmus

Blended wing body (BWB) is a very advantageous design in terms of low fuel consumption, low emission and low noise levels. Because of these advantages, the BWB is a…

Abstract

Purpose

Blended wing body (BWB) is a very advantageous design in terms of low fuel consumption, low emission and low noise levels. Because of these advantages, the BWB is a candidate to become the commercial passenger aircraft of the future by providing a paradigm shift in conventional designs. This paper aims to propose a key design parameter for wing sizing of subsonic BWB and a performance parameter for calculating the lift/drag ratio values of BWBs.

Design/methodology/approach

The parameter proposed in the study is based on the square/cube law, that is, the idea that the wetted area is proportional to the power of 2/3 of the weight. Data on the weight, wing area, wingspan, lift-to-drag (L/D) ratio for 19 BWB used in the analyzes were compiled from the published literature and a theoretical methodology was developed to estimate the maximum lift to drag ratio of BWBs. The accuracy of the proposed key design parameter was questioned by comparing the estimated L/Dmax values with the actual values.

Findings

In the current study, it is claimed that the wingspan/(take-off gross weight)(1/3) parameter provides an L/D efficiency coefficient regardless of aircraft size. The proposed key design parameter is useful both for small-scale BWB, that is unmanned aerial vehicles BWB and for large-scale BWB designs. Therefore, the b/Wg(1/3) parameter offers a dimensionless L/D efficiency coefficient for BWB designs of different scales. The wetted aspect ratio explains how low aspect ratio (AR)-BWB designs can compete with high AR-tube-and-wing designs. The key parameter is also useful for getting an idea of good or bad BWB with design and performance data published in the literature. As a result, reducing the blending area and designing a smaller central body are typical features of aerodynamically efficient BWB.

Originality/value

As the role of the square/cube law in the conceptual aircraft design stage has not been sufficiently studied in the literature, the application of this law to BWBs, a new generation of designs, makes the study original. Estimation of the wetted area ratio using only wingspan and gross weight data is an alternative and practical method for assessing the aerodynamic performance of the BWB. According to the model proposed in the current study, reducing the take-off gross weight of the BWBs using lighter building materials and designing with a larger wingspan (b) are the main recommendations for an aerodynamically efficient BWB.

Details

Aircraft Engineering and Aerospace Technology, vol. 94 no. 3
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 10 August 2018

Ming Qiu, Rui Zhang, Yingchun Li, Hui Du and Xiao Xu Pang

The MoS2/graphite composite coatings modified by La2O3 through spraying technique were successfully prepared on the inner rings of spherical plain bearings. As a…

Abstract

Purpose

The MoS2/graphite composite coatings modified by La2O3 through spraying technique were successfully prepared on the inner rings of spherical plain bearings. As a comparison, unmodified coatings were also prepared. This paper aims to study the La-modified MoS2/graphite composite coating experimentally and improve the tribological performance of self-lubricating spherical plain bearings.

Design/methodology/approach

The performance of La2O3 toward the friction coefficient, temperature rise and wear rate of the coatings was studied by a self-made tribo-tester under different swing cycles. And the texture, surface morphology and element composition of the coatings were characterized by scanning electron microscope, energy dispersive spectroscopy and X-ray diffractometry.

Findings

The additives La2O3 refined the coatings’ microstructure and improved the tribological properties of the coatings. The oxidation of Mo + 4 to Mo + 6 was effectively inhibited. And the amount of abrasive grains, peeling pits and local cracks on the coatings surface decreased and homogeneous lubricating films formed, which were attributed to the existence of La2O3. The wear mechanisms of unmodified coatings were severe abrasive wear, adhesive wear and delamination wear. However, it exhibited superior wear resistance of the La-modified coatings to unmodified coatings, presenting slight abrasive wear and adhesive wear. The service life of bearings was prolonged under the protection of the modified coatings.

Originality/value

The paper proposed a new modified MoS2/Graphite composite coating for the self-lubricating spherical plain bearings. The investigation on the friction, wear and temperature increase behaviors and the wear mechanisms of the coatings are beneficial to prolonging the service life of the self-lubricating spherical plain bearings.

Details

Industrial Lubrication and Tribology, vol. 70 no. 8
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 9 July 2021

Seyhun Durmus

As measuring flight performance by experimental methods requires a lot of effort and cost, theoretical models can bring new perspectives to aircraft design. This paper…

Abstract

Purpose

As measuring flight performance by experimental methods requires a lot of effort and cost, theoretical models can bring new perspectives to aircraft design. This paper aims to propose a model on the direct calculation of wetted area and L/Dmax.

Design/methodology/approach

Model is based on idea that the wetted area is proportional to aircraft gross weight to the power of 2/3 (Wg2/3). Aerodynamic underpinning of this method is based on the square–cube law and the claim that parasitic drag is related to the Swet/Swing. The equation proposed by Raymer was used to find the L/Dmax estimate based on the calculated wetted area. The accuracy of the theoretical approach was measured by comparing the L/Dmax values found in the reference literature and the L/Dmax values predicted by the theoretical approach.

Findings

Proposed theoretical L/Dmax estimate matches with the actual L/Dmax data in different types of aircraft. Among the conventional tube-wing design, only the sailplanes have a very low Swet/Swing. The Swet/Swing of flying wings, blended wing bodies (BWBs) and large delta wings are lower than conventional tube-wing design. Lower relative wetted area (Swet/Swing) is the key design criterion in high L/Dmax targeted designs.

Originality/value

The proposed model could be used in wing sizing according to the targeted L/Dmax value in aircraft design. The approach can be used to estimate the effect of varying gross weight on L/Dmax. In addition, the model contributes to the L/Dmax estimation of unusual designs, such as variable-sweep wing, large delta wings, flying wings and BWBs. This study is valuable in that it reveals that L/Dmax value can be predicted only with aspect ratio, gross weight (Wg) and wing area (Swing) data.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 6
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 17 March 2022

Longfei Sun, Yingchun Le, Junling Wu and Long Lin

The purpose of this study is to reduce the gloss of the surface of silk fabrics, by treating the fabrics with tea and matting agent, to imitate the aging and retro effects…

Abstract

Purpose

The purpose of this study is to reduce the gloss of the surface of silk fabrics, by treating the fabrics with tea and matting agent, to imitate the aging and retro effects of silk artefacts.

Design/methodology/approach

Silk fabrics were treated with different processing techniques. The aged appearance and surface gloss of the silk fabrics were characterised by sensory analysis, measurement of reflectivity, scanning electron microscopy, measurement of brightness and chroma to identify the influential factors.

Findings

The application of matting agent on silk fabrics could reduce the lustre of silk fabrics. Treated with matting agent and tea pigments, silk fabrics could be “aged” to achieve retro effects within a relatively short period of time. A number of other factors and mechanisms that affect the reflectivity of the silk fabrics were also identified.

Research limitations/implications

There is no definite index to evaluate the antique effect of fabrics.

Practical implications

The method developed through this study provided a simple and practical solution to achieving aging and retro effects on silk fabrics.

Originality/value

The method for reducing the lustre of silk fabrics by treating them with matting agent is novel and the finding of the relationships among reflectivity and brightness and chroma is original.

Details

Pigment & Resin Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 12 August 2022

Kang Liu, Yingchun Bai, Shouwen Yao and Shenggang Luan

The purpose of this paper is to develop a topology optimization algorithm considering natural frequencies.

Abstract

Purpose

The purpose of this paper is to develop a topology optimization algorithm considering natural frequencies.

Design/methodology/approach

To incorporate natural frequency as design criteria of shell-infill structures, two types of design models are formulated: (1) type I model: frequency objective with mass constraint; (2) type II model: mass objective with frequency constraint. The interpolation functions are constructed by the two-step density filtering approach to describe the fundamental topology of shell-infill structure. Sensitivities of natural frequencies and mass with respect to the original element densities are derived, which will be used for both type I model and type II model. The method of moving asymptotes is used to solve both models in combination with derived sensitivities.

Findings

Mode switching is one of the challenges faced in eigenfrequency optimization problems, which can be overcome by the modal-assurance-criterion-based mode-tracking strategy. Furthermore, a shifting-frequency-constraint strategy is recommended for type II model to deal with the unsatisfactory topology obtained under direct frequency constraint. Numerical examples are systematically investigated to demonstrate the effectiveness of the proposed method.

Originality/value

In this paper, a topology optimization method considering natural frequencies is proposed by the author, which is useful for the design of shell-infill structures to avoid the occurrence of resonance in dynamic conditions.

Details

Engineering Computations, vol. 39 no. 8
Type: Research Article
ISSN: 0264-4401

Keywords

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