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To analyse the dome structure of the lean premixed swirled combustor, the influences of lance tip shapes, inflow air flow rates, numbers and locations of fuel nozzles and head expansion ratios on the combustion flame, flow field and flame dynamic response were investigated by computational fluid dynamics. The results show that the flame shape remains unchanged when the air velocity increases to a certain value. Increasing the number of fuel holes on the pressure surface, the high heat release rate area is concentrated in the root of the central recirculation zone. While increasing the number of fuel injectors on the pressure side and suction side makes the flame root temperature of the central recirculation zone lower, indicating a tendency to reduce the thermal NOx. Increasing the flame tube diameter helps the central recirculation zone to expand radially, resulting in longer flame branches. The axial length of flame will be shortened by changing the centre-lance tip from flat to ellipse. The amplitude and phase of flame transfer function are not affected by changing the centre-lance tip face shape, but the phase of flame transfer function is obviously changed by increasing the number of fuel holes.

Five kinds of multi-head burners with different structures were discussed according to potential flow theory in this paper. Three cases were selected for further numerical simulation from the consideration of cross fire, wall temperature and flow field. The influence of the rotation direction of the main stage and central class burner on the combustion characteristics was investigated by computational fluid method. The results show the rotation direction of the main swirlers are beneficial to the cross fire, but it will cause hot spots in the asymmetric flow field, which will affect the NOx emission and the cooling of the liner. The tulip-shaped flame is longer when the pilot swirler is counter rotating with main swirlers. When all swirlers rotate in the same direction, there is only one tulip-shaped flame. If the rotations of two adjacent main swirlers are different, a stable pair of tulip-shaped flames and a pair of open flames are produced.

In searching for the optimal control strategy of sub-module capacitance voltage equalization of Modular Multilevel Converter (MMC), the most important issue is how to address the significant increase in computing time of the controller, switching frequency of the sub-module, device switching loss and MMC fault rate led by the increase in the number of sub-modules of the upper/lower bridge arm of the MMC. Therefore, this paper proposes a control strategy based on the retaining factor method + improved quick sort, namely, an improved quick sort algorithm is used to sort the sub-module capacitance voltages to reduce the amount of computation of the MMC controller; at the same time, a retaining factor is introduced to participate in the improved quick sort to significantly reduce the switching frequency of the sub-module. MMC of large ship grid-connected photovoltaic power system is taken as a research object in this paper, a 31-level MMC model is built in Matlab/Simulink. Simulation results verify that the improved quick sort has a good rapidity compared to the algorithms of bubble sort, quick sort, bidirectional bubble sort, and improved merge sort, that the retention factor method has a good frequency reduction effect, and that the proposed retention factor + improved quick sort can provide a good performance compared to improved quick sort and retention factor + improved merge sort under conditions of the normal operation and introducing disturbance. [ABSTRACT FROM AUTHOR]

The vehicle platoon lane changing is significant for alleviating road congestion and diminishing transportation energy consumption. However, the lane changing strategy for a group of vehicles is still a great challenge in this field. This paper investigates the vehicle platoon lane changing problems, in which the safety and efficiency in the lane changing procedure are both taken into consideration. Since the safety of the platoon lane changing would be affected by the lane changing gap and the length of the platoon, a novel platoon lane changing strategy is proposed by using the deep Q‐network. In detail, the proposed platoon lane changing strategy contains two layers, where the first one is a decision layer and the other one is the verification layer. In the decision layer, the deep Q‐network is employed to improve the lane changing efficiency. Then, the verification layer is presented to enhance the platoon lane changing safety. In final, some typical platoon lane changing scenarios are provided in an existing ramp containing a vehicle platoon and some random vehicles. The related numerical simulations are conducted to validate the feasibility and effectiveness of the proposed approaches. [ABSTRACT FROM AUTHOR]

This paper investigates the vehicle platoon control problems, in which the road-friction coefficient is taken into consideration. In order to improve the vehicle platoon safety in various road-friction conditions, an optimal spacing policy is proposed for the vehicle platoon. In detail, an intervehicle space optimization framework is developed by using a safety cost function and the gradient decent method. In this way, the optimal intervehicle spacing headway is presented such that the vehicle can be safely driven to the desired platoon under various road-friction conditions. Then, based on the proposed optimal spacing policy, we transform this optimal spacing vehicle platoon control problem into a moving target tracking problem. An adaptive distributed integrated sliding mode (DISM)-based vehicle platoon control scheme is proposed such that the vehicles can effectively follow the presented optimal spacing platoon. Moreover, the stability of the proposed vehicle platoon system is strictly analyzed and numerical simulations are provided to verify the proposed approaches., Author(s): Lei Zuo (corresponding author) [1]; Duo Meng [1]; Jinqi Zhang [1] 1. Introduction Recently, increasing attention has been paid to the vehicle platoon control due to its significant benefits [...]