Performance analysis of one dimensional BC 2 N for nanoelectronics applications

2018 ◽  
Vol 102 ◽  
pp. 33-38 ◽  
Author(s):  
Wei Hong Lim ◽  
Afiq Hamzah ◽  
Mohammad Taghi Ahmadi ◽  
Razali Ismail
Keyword(s):  
Performance Analysis ◽  
One Dimensional

Altitude Effects on the Performance of Small Radial Turbomachinery: Part I — Compressor Impellers

2016 ◽  
Author(s):  
Dries Verstraete ◽  
Kjersti Lunnan
Keyword(s):  
Reynolds Number ◽  
Performance Analysis ◽  
Rotational Speed ◽  
Pressure Ratio ◽  
Unmanned Aircraft ◽  
Good Match ◽  
One Dimensional ◽  
Design Changes ◽  
Current Article ◽  
The Impact

Small unmanned aircraft are currently limited to flight ceilings below 20,000 ft due to the lack of an appropriate propulsion system. One of the most critical technological hurdles for an increased flight ceiling of small platforms is the impact of reduced Reynolds number conditions at altitude on the performance of small radial turbomachinery. The current article investigates the influence of Reynolds number on the efficiency and pressure ratio of two small centrifugal compressor impellers using a one-dimensional meanline performance analysis code. The results show that the efficiency and pressure ratio of the 60 mm baseline compressor at the design rotational speed drops with 6–9% from sea-level to 70,000 ft. The impact on the smaller 20 mm compressor is slightly more pronounced and amounts to 6–10%. Off-design changes at low rotational speeds are significantly higher and can amount to up to 15%. Whereas existing correlations show a good match for the efficiency drop at the design rotational speed, they fail to predict efficiency changes with rotational speed. A modified version is therefore proposed.

Evaluation and Enhancement of a One-Dimensional Performance Analysis Method for Centrifugal Compressors

2014 ◽  
Author(s):  
Enrico Klausner ◽  
Uwe Gampe
Keyword(s):  
Performance Analysis ◽  
Performance Prediction ◽  
Standard Procedure ◽  
Flow Analysis ◽  
Measurement Data ◽  
Theoretical Models ◽  
Analysis Method ◽  
Centrifugal Compressors ◽  
One Dimensional ◽  
The One

The one-dimensional flow analysis along a mean streamline is an appropriate and established procedure for initial design and performance analysis of turbomachinery. One such method for performance analysis of centrifugal compressors was published by Aungier in the 1990s. The latest description of Aungier’s performance prediction model was applied to a set of centrifugal compressor stages published in literature. For each test case the whole performance map was calculated and compared with measurement data. The calculation results correspond well with measured data over a wide operating range. However, near choke or stall the mean streamline performance prediction deviates from measurements. After evaluation of this “standard” mean streamline model specific loss correlations, e.g. for choking, incidence and shock losses were replaced by theoretical models. The aim was to implement a more physical based loss model which is able to predict the performance of compressor stages outside the limits of the standard procedure. The modified procedure was again validated against measurements of the above mentioned compressor stages. The modified procedure gives a better prediction of operating performance and behavior. Shortcomings of the procedure are still the overestimation of vaneless diffuser losses at low mass flow rates and the uncertainty in prediction of choke limit. In conclusion recommendations for advancement of the one-dimensional performance analysis method are given.

Self-Entrainment Characteristics and Performance of a Compact Air Ejector

2008 ◽  
Author(s):  
Kartik V. Bulusu ◽  
Charles A. Garris
Keyword(s):  
Performance Analysis ◽  
Computer Program ◽  
Constant Pressure ◽  
Automotive Applications ◽  
Refrigeration System ◽  
One Dimensional ◽  
Constant Area ◽  
Dimensional Parameters ◽  
And Performance ◽  
Air Ejector

A one dimensional method of analysis and experimentally determined entrainment and compression ratios are presented with considerations made for constant pressure and constant area mixing. A set of three nozzles, one converging and two converging diverging, were used to study the isentropic characteristics of the ejector performance. Ejector efficiencies are calculated using the turbomachinery analogue of compressors where adiabatic and complete mixing of primary and secondary fluids is assumed before discharge. Efficiencies are characterized against non-dimensional parameters chosen in context. A generalized algorithm and corresponding MATLAB™ based computer program was developed for performance analysis. While exploring the possibility of a refrigeration system for automotive applications where the size of the ejector could play an important role, a compact experimental ejector was designed and tested.

Dynamic Performance Analysis of Submarine Screw Compressor Deballasting System

2013 ◽  
Vol 706-708 ◽  
pp. 1300-1304
Author(s):  
Ke Long Zhang ◽  
Shi Hu Ma ◽  
Xing Sheng Lao
Keyword(s):  
Performance Analysis ◽  
Cross Section ◽  
Dynamic Performance ◽  
Low Pressure ◽  
Gas Pressure ◽  
Screw Compressor ◽  
Ballast Tank ◽  
Circular Section ◽  
One Dimensional ◽  
Section Model

One dimensional dynamic model for submarine low pressure screw compressor deballasting system performance analysis is developed. Cross section of outer shell of ballast tank is described as cylinder, one dimensional flow equations combined with screw compressor performance model are employed to describe compressors flow characteristic. Coupled effect between gas pressure in ballast tank and discharging performance of screw compressor is considered in the presenting model as gas leakage during compressing process is taken into account. Deballasting duration for one certain submarine model is calculated using the developed model, and the result agrees well with that obtained by using Chinese state code for submarine low pressure system design. For different cross section tank models as circular section model, parabolic section model and trapezoidal section model, dynamic performance of screw compressor deballasting system is studied using the validated model. Gas pressure in tank, dropping speed of tank water surface and draft of submarine are simulated, and the results show that little difference of deballasting duration is caused by changing tank cross section. The most stable deballasting process is achieved by using a circular section tank. Deballsting performance is also studied as tonnage of submarine and volume of ballast tank change and commonsense conclusions are obtained.

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