Investigation on new low cost electronically controlled fuel metering systems for small gas turbine engines

This work introduces two new lost cost, electronically controlled fuel metering systems for small gas turbine engines, particularly applicable in remotely piloted vehicles. The first one incorporates a diaphragm operated flat-seat bypass valve to maintain a constant differential pressure across the metering valve, which is actuated by a digital linear actuator. In the second one, both the metering and the bypass valves are controlled by two independently operated digital linear actuators. The mathematical models for the first fuel metering system, were created and used for computer simulation. Next, after preparing the experimental test set-up, the manufactured prototype was tested and the models for both the steady state and the dynamic response were validated. Three design optimization criteria, fuel flow linearity, low sensitivity to the design parameters changes and fast dynamic response were examined to improve the performance of the proposed fuel metering system. Finally, a multi-objective optimization technique was developed and implemented to obtain the best design parameters of the system. For the second fuel metering system, first the mathematical models for both the steady state and dynamic response were developed. Next, due to the flexibility offered by this system, different control strategies for controlling the digital linear actuators during the normal operation mode of the actuators and also during the back-up operation modes were introduced and investigated. Finally, to investigate the impact of different control strategies on the dynamic response of the engine, a dynamic model for the engine was also developed and used. At the end, four available fuel metering systems, including the two new ones, were compared regarding their deviation from the fuel flow linearity, dynamic response and the cost

Design, Fabrication and Evaluation A New Mechanism to Automatic Weight Transfer Control System on A Tractor

Increasing tractor weight during agricultural operations is one of ways to optimization the performance of tractor tires interacting with soil. One of these methods is adding weight on the front of the tractor, which leads to better engagement of front tires with soil. In four-wheel drive tractors also causes better steering wheel drive tractors, in addition it prevents from weight transfer to the rear of the tractor, which causes overturning. In this research, a new approach has been proposed that proves automatic weight transfer is possible by putting some lightweight instead of main weights on the front of the tractor. To do this, a number of weights to a specified amount were added on the front of the tractor which could be moved by using a mechanical joint and a hydraulic jack (considering working condition and ground conditions). Traction force and slop of land that have the most impact on weight transfer were measured by a dynamometer and an inclinometer. Also the critical values of these parameters were controlled by an electronic circuit. Results prove that the applied system on the tractor was able to control dynamic weight transfer also the longitudinal balance on the tractor was investigated by performing an experiment on a sloping surface, and good results were detained

Moisture-Dependent Some Engineering Properties of Soybean Grains

This study was carried out to evaluate the effect of moisture content on some physical properties and mechanical behaviour under compression load of soybean grains. Four levels of moisture content ranging from 6.92 to 21.19% d.b. were used. The average length, width, thickness, arithmetic and geometric mean diameter, surface area, thousand grains mass and angle of repose increased as the moisture content increased from 6.92 to 21.19%. As the moisture content increased from 6.92 to 21.19% d.b., the bulk density and true density were found to decrease from 650.95 to 625.36 kg/m3 and 1147.86 to 1126.43 kg/m3 respectively, while the porosity was found to increase from 43.29 to 44.48%. The static coefficient of friction of soybean increased linearly against various surfaces as the moisture content increased from 6.92 to 21.19% d.b. The rupture energy of the grains increased in magnitude with an increase in moisture content, while rupture force decreased

Comparison of Mechanical Properties of Wheat and Barley Straw

The objective of this work was to compare the mechanical properties of wheat and barley straw. The experiments were conducted at moisture contents of 10.24% and 10.76% w.b. for wheat and barley straw, respectively, and three internode positions down from the ear. The average shear strength for wheat and barley straw varied from 6.81 to 7.12 MPa and 3.90 to 4.49 MPa, respectively. The specific shearing energy of wheat and barley straw increased from 21.85 to 25.74 mJ/mm2 and 18.79 to 19.85 mJ/mm2, respectively, towards the third internode position. The bending stress and Young’s Modulus of wheat and barley straw increased towards the first internode position. The results showed that the mechanical properties of wheat and barley straw were statistically different

Effect of Moisture Content and Loading Rate on the Shearing Characteristics of Barley Straw by Internode Position

This research was conducted to evaluate the effect of moisture content, internode position and loading rate on the shearing characteristics of barley straw in terms of shear strength and shearing energy. The characteristics were determined at three moisture levels: 10, 15 and 20 % w.b., three loading rates: 5, 10 and 15 mm/min and three internodes: first, second and third internode. The results showed that both the shear strength and shearing energy increased with an increase in moisture content and loading rate and towards the third internode position. The average shear strength was obtained as 5.08 MPa varying from 3.68 to 6.18 MPa, while the average shearing energy was calculated as 100.93 mJ ranging from 65.17 to 131.06 mJ. The shear strength of the barley straw increased from 4.09 to 5.03 MPa, 4.84 to 5.25 MPa and 5.15 to 5.94 MPa for the first, second and third internodes, respectively, as the moisture content increased. The shearing energy of the straw also varied from 70.44 to 99.82 mJ, 92.46 to 121.25 mJ and 102.33 to 122.09 mJ for the first, second and third internodes, respectively

Modified Atmosphere Packaging: A Progressive Technology for Shelf-Life Extension of Fruits and Vegetables

Packaging and storage are the final phases in the food industry. Quality preservation, improving safety and reduction of postharvest losses waste are some objectives of the packaging engineering. One of techniques that widely used in packaging of fruits and vegetables are modified atmosphere packaging (MAP). In MAP for fresh fruits and vegetable the air of packaging headspace replaces with a predetermined atmospheric gases different in proportion from that of air. Oxygen, carbon dioxide and nitrogen are the main gases used in MAP for injection to the headspace of pack. The choice and ratio of gases are very dependent upon the material that being packed. respiration rate of crop, O2 and CO2 permeability of package material, volume of headspace present inside the package and storage temperature are some factors that affect the quality of MA packaging. Polymeric films are widely used in MAP engineering. The most application of polymeric films for MAP are in flexible package structures. In many cases the plastic packaging films are combined with one another or with other materials such as paper or aluminum through coating, lamination, coextrusion and metallization processes. The equipment used in MAP is divided into two main categories: pillow wrap and chamber. Flexible pillow wrapping machines are composed of Horizontal Form-Fill-Seal (HFFS) machines and Vertical Form-Fill-Seal (VFFS) systems. This paper reviews some recent developments in MAP technology applied for fruits and vegetables

An Image Processing Based Approach for Detection of Nitrogen Status in Winter Wheat Under Mild Drought Stress

Abstract. Nitrogen is one of the most important agricultural inputs affecting crop growth, yield and quality in rain-fed cereal production. In this study an image processing based approach was used for detection of nitrogen status in winter wheat. Four N fertilization rates (0, 60, 120 and 240 kg N ha -1 , in total) and two water regimes (irrigated and non-irrigated) were applied to winter wheat. Digital images of the plant canopy were acquired using a Canon camera during the growing season 2012. Different indices were extracted by processing of the images. According to the statistical analyses, all the indices were affected by both N and water supplies. However, Rm, RMB, NRMB, Hue and INT were less sensitive to water supply. Among the indices, crop coverage (CC) showed better results for detection of nitrogen status of the plant. We conclude that digital cameras can be used to assess nitrogen status of winter wheat

Evaluation of an electronic nose system for characterization of pomegranate varieties

The electronic nose (e-nose) would simulate the human sense (smell) to identify and realize the complex aromas by employing a chemical sensors array. One of the most common sensors used in electronic nose systems are metal oxide semiconductor (MOS) sensors. In this research, a low cost e-nose system based on six metal oxide semi-conductor (MOS) sensors as a non-destructive instrument for recognition pomegranate varieties is investigated. Principal component analysis (PCA) and linear discriminant analysis (LDA) techniques are used for this purpose. The proposed e-nose has a capability of demonstrating a clear difference in aroma fingerprint of pomegranate by PCA and LDA analysis. Using LDA analysis, it is possible to identify and to categorize the difference between pomegranate varieties, and based on the results, the classification accuracy of 95.2% was obtained. Sensor array capabilities for classification of pomegranate varieties using loading analysis were investigated too. Results showed high ability of e-nose for distinguishing between the varieties of pomegranates

Design and Simulation of a Vision-Based Automatic Trout Fish-Processing Robot

Today, industrial automation is being applied in a wide range of fields. The initial modeling of robots and mechanical systems together with simulation results in optimal systems. In this study, the designed system is simulated to obtain the required velocities, accelerations and torques of the actuating arms in a vision-based automatic system. Due to the slippery skin of fish and the low friction coefficient, it is not easy to design an optimal tool to handle fish. Since the fish-processing operation is undertaken step by step and provides fish stability, it is essential that the gripper enables different processing operations along the system. The proposed system performs belly-cutting, beheading, gutting, and cleaning stages for different fish sizes, based on the extracted dimensions of the vision system. In the head-cutting section, the average speed of the actuator jack was considered as 500 mm s−1. Under these conditions, the maximum required force to provide this speed was 332.45 N. In the belly-cutting subsystem, the required torque for the stepper motor resulted in 1.79-2.15 N m. Finally, the maximum required torque for the gutting stepper motor was calculated as 0.69 N m in the tested processing capacitie

Development and application of a new low cost electronic nose for the ripeness monitoring of banana using computational techniques (PCA, LDA, SIMCA, and SVM)

Se ha estudiado la posible aplicación de una nariz electrónica basada en semiconductores de óxido metálico (e-nariz) como un instrumento que no sea destructivo para el seguimiento del cambio en la producción de volátiles de plátano durante el proceso de maduración. La propuesta de e-nariz no necesita ningún equipo de laboratorio avanzado o caro y resultó ser fiable en la grabación de las diferencias significativas entre las etapas de maduración. El Análisis de Componentes Principales (PCA), Análisis Discriminante Lineal (LDA), Modelado Suave Independiente de las Analogías de Clases (SIMCA) y Máquinas Soporte de Vectores (SVM) son técnicas utilizadas para este propósito. Los resultados mostraron que la dirección de la e-nariz distingue entre las diferentes etapas de maduración. La nariz electrónica fue capaz de detectar una clara diferencia en la huella digital de aroma de plátano cuando se utiliza el análisis de SVM en comparación con PCA o LDA y SIMCA. Utilizando el análisis de SVM, era posible diferenciar y clasificar las diferentes etapas de maduración de plátanos, y este método fue capaz de clasificar el 98,66% del total de muestras en su grupo respectivo. Las capacidades matrices de sensores en la clasificación de etapas de maduración usan el análisis de la carga y la SVM y SIMCA También se ha visto que conduce a desarrollar un sistema de e-nariz específico mediante la aplicación de los sensores más eficaces y a ignorar los sensores redundantesPotential application of a metal oxide semiconductor based electronic nose (e-nose) as a non-destructive instrument for monitoring the change in volatile production of banana during the ripening process was studied. The proposed e-nose does not need any advanced or expensive laboratory equipment and proved to be reliable in recording meaning¬ful differences between ripening stages. Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA), Soft Independent Modelling of Class Analogy (SIMCA) and Support Vector Machines (SVM) techniques were used for this purpose. Results showed that the proposed e-nose can distinguish between different ripening stages. The e-nose was able to detect a clear difference in the aroma fingerprint of banana when using SVM analysis compared with PCA and LDA, SIMCA analysis. Using SVM analysis, it was possible to differentiate and to classify the different banana ripening stages, and this method was able to classify 98.66% of the total samples in each respective group. Sensor array capabilities in the classification of ripening stages using loading analysis and SVM and SIMCA were also investigated, which leads to develop the application of a specific e-nose system by applying the most effective sensors or ignoring the redundant sensors.peerReviewe