Ejector nozzle design by numerical simulation for the ejector type air-conditioner system

2015 ◽  
pp. 723-728
Keyword(s):  
Numerical Simulation ◽  
Nozzle Design ◽  
Air Conditioner ◽  
Ejector Nozzle

Unsteady Numerical Simulation of Shock Systems in Vaneless Counter-Rotating Turbine

2005 ◽  
Author(s):  
Huishe Wang ◽  
Qingjun Zhao ◽  
Xiaolu Zhao ◽  
Jianzhong Xu
Keyword(s):  
Numerical Simulation ◽  
Mach Number ◽  
Leading Edge ◽  
Turbine Rotor ◽  
Nozzle Design ◽  
Suction Surface ◽  
Rotor Wake ◽  
Wake Interaction ◽  
Unsteady Numerical Simulation ◽  
Almost All

A detailed unsteady numerical simulation has been carried out to investigate the shock systems in the high pressure (HP) turbine rotor and unsteady shock-wake interaction between coupled blade rows in a 1+1/2 counter-rotating turbine (VCRT). For the VCRT HP rotor, due to the convergent-divergent nozzle design, along almost all the span, fishtail shock systems appear after the trailing edge, where the pitch averaged relative Mach number is exceeding the value of 1.4 and up to 1.5 approximately (except the both endwalls). A group of pressure waves create from the suction surface after about 60% axial chord in the VCRT HP rotor, and those waves interact with the inner-extending shock (IES). IES first impinges on the next HP rotor suction surface and its echo wave is strong enough and cannot be neglected, then the echo wave interacts with the HP rotor wake. Strongly influenced by the HP rotor wake and LP rotor, the HP rotor outer-extending shock (OES) varies periodically when moving from one LP rotor leading edge to the next. In VCRT, the relative Mach numbers in front of IES and OES are not equal, and in front of IES, the maximum relative Mach number is more than 2.0, but in front of OES, the maximum relative Mach number is less than 1.9. Moreover, behind IES and OES, the flow is supersonic. Though the shocks are intensified in VCRT, the loss resulted in by the shocks is acceptable, and the HP rotor using convergent-divergent nozzle design can obtain major benefits.

Numerical Simulation and Optimal Design Investigation on Air Duct of Floor Standing Air-Conditioner

2011 ◽  
Vol 308-310 ◽  
pp. 563-567
Author(s):  
Zhong Min Wan ◽  
Zu Yi Zheng ◽  
Huan Xin Chen ◽  
Jun Liu ◽  
Ting Xiang Jin
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Aerodynamic Characteristic ◽  
Volume Flow Rate ◽  
Structural Characteristics ◽  
Flow Characteristics ◽  
Volume Flow ◽  
Numerical Results ◽  
Air Conditioner ◽  
Duct Flow

According to the structural characteristics of floor standing air-conditioner，three dimensional numerical model of air duct system for a certain floor standing air-conditioner is developed to simulate aerodynamic characteristic of the air duct. Flow characteristics and deficiency of air duct for original floor standing air-conditioner are analyzed, and the optimal schemes of air duct are raised and numerical simulation has been carried on to obtain aerodynamic characteristic of the new air duct. The numerical results show that the volume flow rate of air-conditioner with new air duct is increased by 6.1%. The experimental results of air-conditioner with new air duct show the volume flow rate of new air duct is promoted by 5.6% at the same approximate noise level. The numerical results agree well with the previous experiment.

A Numerical Simulation of an Air Conditioning System in Office Using Weak Airflow

2003 ◽  
Author(s):  
Sensuke Shimizu ◽  
Haruo Terasaka ◽  
Akira Yamada
Keyword(s):  
Numerical Simulation ◽  
Air Conditioning ◽  
Thermal Environment ◽  
Thermal Sensation ◽  
Air Conditioner ◽  
Air Conditioning System ◽  
The People

The objective in this study is to evaluate thermal environment of a room with an advanced ceiling hidden type air-conditioner using numerical simulation. As the characteristic of the air-conditioner, it supplies a weak airflow from a large inlet to a room. Circulator fans are fixed on the ceiling. Numerical simulation is performed to a room with the air-conditioner. PMV [1] is calculated from the obtained data and thermal sensation of the people is investigated. From the PMV distribution, it was found that this sensation was improved by the advanced air-conditioner.

Simulation Based on CFD to Temperature and Flow Fields of Vertical Air Conditioner Operation

2012 ◽  
Vol 594-597 ◽  
pp. 2106-2111
Author(s):  
Yi Tang ◽  
Jin Feng Wang ◽  
Jing Xie ◽  
Zheng Zhang ◽  
Rui Liu
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Sales Volume ◽  
Air Conditioner ◽  
Meeting Room ◽  
Simulation Based ◽  
Computational Fluid Dynamics Cfd ◽  
China Mainland ◽  
Temperature And Flow Fields

The sales volume of vertical air conditioner in China mainland has developed rapidly. The researches in the field to the operation of vertical air conditioner are lacked since it is hardly to analyze different kinds of operating condition. Computational Fluid Dynamics (CFD) has been applied in engineering with the advance of the computer science and technology. In this article, both temperature and air flow distributions were analyzed to a meeting room which putted a vertical air conditioner. The model was used and the equations for numerical simulation (e.g. energy, residual, continuity, etc) were chosen as second order to get the higher accuracy. The results to simulation were showed reasonable and could offer a reference to the practical.

scholarly journals MODELING OF GAS-DYNAMIC PROCESSES IN THE ELEMENTS OF IMPULSE EJECTOR

2021 ◽  
pp. 66-72
Author(s):  
G. O. Voropaiev ◽  
Ia. V. Zagumennyi ◽  
N. V. Rozumnyuk
Keyword(s):  
Numerical Simulation ◽  
High Pressure ◽  
Flow Rate ◽  
Gas Flow ◽  
Dynamic Processes ◽  
Stable Operation ◽  
Operating Pressure ◽  
Gas Generator ◽  
Gas Dynamic ◽  
Ejector Nozzle

The paper presents the numerical results on gas-dynamic processes in various elements of the impulse ejector, including pre-chamber, supersonic nozzle and mixing chamber, to determine optimal geometric parameters providing the given flow rate characteristics. At an extra-high pressure of the ejecting gas (>100 bar) it is impossible to create a nozzle design with continuously changing cross-sectional area and limited nozzle length. So, it is necessary to place a pre-chamber between the gas generator and the ejector nozzle for throttling full gas pressure. In order to optimize the pre-chamber parameters in the ejector with discrete holes of the gas generator and the operating pressure in the range of 400÷1000 bar, a series of calculations were performed to determine the pre-chamber parameters, ensuring stable operation of the supersonic annular nozzle at the high pressure of 35÷45 bar and the flow rate of 0.5÷0.6 kg/s. 3D numerical simulation of the gas flow into the pre-chamber through the gas generator holes shows the degree of the flow pattern non-uniformity in the pre-chamber at the ejector nozzle inlet is quite low. This justifies the numerical simulation of gas flow in the ejector in axisymmetric formulation and allows restricting the number of the gas generator holes without inducing significant non-uniformity in the azimuthal direction.

scholarly journals Complex effect of recess depth in nozzle design on the discharge coefficient

2018 ◽  
pp. 43-50
Author(s):  
A. N. Sabirzyanov ◽  
A. N. Kirillova
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Experimental Investigation ◽  
Discharge Coefficient ◽  
Specific Impulse ◽  
Geometrical Parameters ◽  
Nozzle Design ◽  
Complex Effect ◽  
Flow Processes ◽  
Acceptable Agreement

We used contemporary computational fluid dynamics techniques to evaluate how the geometric parameters of a recessed nozzle affect the perfection of flow processes. We verified our numerical simulation and obtained acceptable agreement between numerical and experimental investigation results in terms of specific impulse loss. We plotted the discharge coefficient as a function of the geometrical parameters of a recessed nozzle. Our numerical investigation forms the basis of certain guidelines we developed for designing arc-based recessed nozzles.

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