Unsmooth reversing is one of the most common faults in the four-way reversing valve of air conditioning system, and the airflow in the valve chamber and the shape of the slider of the reversing valve are the main factors in unsmooth reversing. In order to study the influence of the airflow in the chamber and the slider shape on the reversing process, the fluid flow in the valve chamber of a four-way reversing valve is obtained using computational fluid dynamics (CFD) simulations, and the influence of slider structure on slider thrust and resistance of the four-way reversing valve is analyzed. Four-way reversing valves with no-cutting, straight-cutting and arc-cutting sliders are employed to evaluate the reversing characteristics. A pressure measuring device for a four-way reversing valve chamber is designed, which is performed to test the chamber pressure of three different types of sliders of four-way reversing valves. The maximum error of experimental tests and simulations is within 5% of engineering tolerance, so as to verify the reliability of numerical simulation. The results indicate that the chamber pressure and resistance-thrust ratio with the cutting slider are reduced, which is beneficial to the reversing of the four-way reversing valve. Compared with the straight cutting structure, the arc cutting slider four-way reversing valve has a more stable reversing process and better comprehensive reversing performance. The results can provide a theoretical basis for engineers to improve the performance of four-way reversing valves.

The four-way reversing valve is a key component determining whether a heat pump air conditioning system can work. Studying the four-way reversing valve is of great significance for improving the performance of the heat pump air conditioning system. In this paper, the control equation of the sliding block movement process is constructed to simulate the reversing process of the four-way reversing valve in fluid mechanics, and a detailed study is carried out from the sliding block speed, sliding block acceleration, sliding block force, refrigerant leakage, and other aspects. Research has shown that optimizing the structure of the slider can greatly improve the working performance of the four-way reversing valve. Increasing the height of the slider not only improves the pressure relief ability of the four-way reversing valve and prevents the slider from being damaged by high-pressure gas impact, but also reduces the leakage of refrigerant during the directional process; When reducing the length of the slider, although it will improve the pressure relief capacity of the four-way reversing valve, it also increases the amount of refrigerant leakage. The research results provide a theoretical basis and improvement direction for designers to improve the performance of four-way reversing valves.

Purpose: The purpose of this study is to determine the effects of post-purchase regret felt by consumers buying fashion products and their efforts to reverse their regrets, on dissatisfaction and their repurchase intention. Design/Methodology/Approach: The population of this research consists of the consumers in Gaziantep who buy fashion products and regret their purchase for any reason. Out Of non-probability sample methods, convenience sampling was used. Thinking that this can represent the population of the study, the sample number was determined as 441. In order to test the hypotheses, Smart PLS 3 (Partial Least Squares) statistics programme was used. Bootstrapping technique was used to test the hypotheses intended to be measured in the study. Findings: The tests show that regret positively affect dissatisfaction (ß=,544, p<0,001) and the effort to reverse the feeling of regret. In addition, regret negatively affect repurchase intentions. Another variable, dissatisfaction negatively affect re-purchasing intention and regret reversing efforts positively affect re-purchasing intentions. Research limitations: Because the study is restricted by time, cost, accessibility, control difficulties; the whole of the population was not reached. The study is conducted with the data obtained from 441 consumers in Gaziantep and evaluations made by consumers who prefer ready-made wear. Practical implications: The results show that regret experienced in the past negatively affect re-purchasing process. It has been determined that the consumers can diminish their regret when they try to reverse it and this situation strengthens their re-purchasing intentions. Hence, it is thought to be beneficial to ensure that consumers are aware of their regrets and to focus on strategies that help enterprises to reverse this regret. Originality/value: Even though there are studies that associate regret with dissatisfaction and repurchase intentions, there are very few studies that focus on regret reversing efforts. There is no such study in local literature. Therefore, this study is original in these aspects and it is thought that it will contribute to the body of literature.

In this paper, an offshore airborne wind energy (AWE) farm consisting of three non-reversing pumping mode AWE systems is modelled and simulated. The AWE systems employ permanent magnet synchronous generators (PMSG). A direct interconnection technique is developed and implemented for AWE systems. This method is a new approach invented for interconnecting offshore wind turbines with the least number of required offshore-based power electronic converters. The direct interconnection technique can be beneficial in improving the economy and reliability of marine airborne wind energy systems. The performance and interactions of the directly interconnected generators inside the energy farm internal power grid are investigated. The results of the study conducted in this paper, show the directly interconnected AWE systems can exhibit a poor load balance and significant reactive power exchange which must be addressed. Power control strategies for controlling the active and reactive power of the AWE farm are designed, implemented, and promising results are discussed in this paper.