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This paper presents an analysis of approaches to ensuring the performance of a ramjet combustor using an unconventional method of measuring the thrust in testing an experimental model of a liquid-fuel combustor under flight conditions simulated by a fired heater. The thrust and drag of the combustor model were measured in firing tests with an attached air duct using a thrust meter. Thrust is a parameter that characterizes the energy potential of any engine. The conventional method of determining the thrust and economic characteristics of a heat engine involves lengthy multi-parameter studies and calculations of the operation performance. The new method allows one to detect the effect of any parameter or element of the structure on the physical process in a combustor in units of the developed thrust and evaluate the change in any parameter by the thrust level directly in firing tests. The proposed thrust measurement system makes it possible to refine the strategy of implementing the combustor operation at an early stage of testing, thus reducing the amount of intermediate calculations and saving a huge amount of time and money. This, combined with static pressure measurements along the combustor length, allows a guaranteed prediction of the direction of search for improving the operation performance. Ways are shown to improve the ramjet combustor performance using a thrust meter to evaluate the overall engine performance under conditions of limited technical and methodical possibilities in firing tests. [ABSTRACT FROM AUTHOR]

The traditional thermal environment management of the passenger compartment adopts the unified regulation method. Air distribution formed in this manner often causes thermal comfort and energy consumption problems. In view of the problems of conventional airflow organization, a new air supply strategy-variable air volume and temperature strategy is proposed. In this air supply strategy, variable air volume and variable temperature air supply is carried out according to the characteristics of thermal comfort requirements of passengers in different periods and positions in the cabin. STAR-CCM + software coupled with THESUES-FE software was implemented and compared with different air supply methods. The performance of the air supply strategy was evaluated based on PMV-PPD evaluation index. The results show that the variable air volume variable temperature air supply strategy has certain advantages and improves the thermal comfort level of the crew cabin. The cooling capacity of the automobile air conditioning is allocated effectively, thus improving the satisfaction of the occupants to the thermal environment. This strategy not only saves energy, but also improves the cooling effect in the cabin. [ABSTRACT FROM AUTHOR]

Personalized air conditioning systems are widely used in sleeping environments, where a sleeping human body is always immobile through night. The ventilation performance optimization of air conditioning system becomes necessary, and the influences from different supply air parameters were investigated in this study, including supply air flow rate and temperature, supply air outlet height and fresh air flow rate. To understand the effects of supply air parameters on ventilation performance, the occupied zone air flow field, air change efficiency, CO2 concentrations and CO2 concentrations distributions inside the room were numerically studied. It was indicated that placing the supply air outlet at lower levels of 1.1 and 0.8 m could directly deliver cooling air to the thermal manikin, leading to a much higher air change efficiency of around 70%. The air temperature of the occupied zone could not be well cooled down for the supply air outlet at a height of 0.8 m. Meanwhile, the higher supply air flow rate may cause significant draft risk. Finally, considering the ventilation performance and draft risk, a set of the supply parameters is suggested for this personalized air conditioning system. [ABSTRACT FROM AUTHOR]

Modeling of the aerodynamic processes involved in the ventilation of a large production enclosure containing electrical equipment requiring special conditions for air humidity and temperature was performed. A physical-mathematical model of the aerodynamics of ventilation of a production enclosure is presented, taking into account heat exchange with air and the surface of the equipment present in a building and mass exchange with the ambient environment by air filtration through the structural elements. The computational results for non-stationary displacement of air with high humidity from the building by means of ventilation with dried air are presented. The characteristic time of purification of air from excess moisture with air supplied to various parts of a building was determined. [ABSTRACT FROM AUTHOR]