Application of the Geared Turbofan With Constant Volume Combustor on Short-Range Aircraft: A Feasibility Study

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Ramón F. Colmenares Quintero ◽  
Rob Brink ◽  
Stephen Ogaji ◽  
Pericle Pilidis ◽  
Juan C. Colmenares Quintero ◽  
...  
Keyword(s):  
Feasibility Study ◽  
Short Range ◽  
Flow Behavior ◽  
Operating Cost ◽  
Constant Volume ◽  
Superior Performance ◽  
Wave Rotor ◽  
Environmental Aspects ◽  
Combustion Technology ◽  
Further Development

Recently a considerable effort was made to understand the gas- and thermodynamics of wave rotor combustion technology. Pressure-gain combustors potentially have superior performance over conventional combustors due to their unsteady flow behavior. Wave rotor combustion provides semiconstant volume combustion and could be integrated in the steady-flow gas turbine. However, a feasibility study to assess the economical and environmental aspects of this concept has not been conducted for short-range missions. Preliminary multidisciplinary design framework was developed to assess novel and radical engine cycles. The tool comprises modules to evaluate noise, emissions, and environmental impact. Uncertainty can be accounted for with Monte Carlo simulation. The geared turbofan with constant volume combustor is simulated and benchmarked against a baseline geared turbofan engine. Results indicate that the former complies with CAEP/6 and FAR Part 36 regulations for noise and emissions. Furthermore, the acquisition cost of the engine is higher, but the engine direct operating cost decreases by 25.2%. The technology requires further development to meet future noise and emission requirements.

Application of the Geared Turbofan With Constant Volume Combustor on Short-Range Aircraft: A Feasibility Study

2009 ◽  
Author(s):  
Fernando Colmenares Quintero ◽  
Rob Brink ◽  
Stephen Ogaji ◽  
Pericles Pilidis ◽  
Juan Carlos Colmenares Quintero ◽  
...  
Keyword(s):  
Feasibility Study ◽  
Short Range ◽  
Operating Cost ◽  
Constant Volume ◽  
Superior Performance ◽  
Wave Rotor ◽  
Environmental Aspects ◽  
Direct Operating Cost ◽  
Combustion Technology ◽  
Further Development

Recently a considerable effort was made to understand the gas- and thermodynamics of wave rotor combustion technology. Pressure-gain combustors potentially have superior performance over conventional combustors due to their unsteady flow behaviour. Wave rotor combustion provides semi-constant volume combustion and could be integrated in the steady-flow gas turbine. However, a feasibility study to assess the economical and environmental aspects of this concept has not been conducted for short-range missions. Preliminary Multidisciplinary Design Framework was developed to assess novel and radical engine cycles. The tool comprises modules to evaluate noise, emissions and environmental impact. Uncertainty can be accounted for with Monte Carlo simulation. The geared turbofan with constant volume combustor is simulated and benchmarked against a baseline geared turbofan engine. Results indicate that the former complies with CAEP/6 and FAR Part 36 regulations for noise and emissions. Furthermore, acquisition cost of the engine is higher, but engine direct operating cost decreases by 25.2%. The technology requires further development to meet future noise and emissions requirements.

Gel Electrolyte Based Supercapacitors with Higher Capacitances and Lower Resistances than Devices with a Liquid Electrolyte

MRS Advances ◽  
2018 ◽  
Vol 3 (22) ◽  
pp. 1261-1267 ◽  
Author(s):  
Belqasem Aljafari ◽  
Arash Takshi
Keyword(s):  
Polymer Electrolytes ◽  
Room Temperature ◽  
Electrochemical Impedance ◽  
Liquid Electrolyte ◽  
Gel Electrolyte ◽  
Superior Performance ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
Gel Electrolytes ◽  
Further Development

ABSTRACTRecently, gel polymer electrolytes (GPEs) have been drawn noteworthy attention for different applications, specifically, for supercapacitors. GPEs could become an excellent substitute to liquid electrolytes (LEs) for making flexible and more durable devices. The performance of two different electrolytes (GPEs and LEs) in multi-wall carbon nanotube based supercapacitors were investigated. In spite of significantly lower conductivity of GPEs than LEs, devices with the gel electrolyte presented a superior performance. More focused has been given in this work on demonstrating the performance of supercapacitors based on GPEs and LEs at different concentrations of the acids ranging from 1M to 3M. Both electrolytes have been characterized at room temperature by making supercapacitors and using cyclic voltammetry, charging-discharging, electrochemical impedance spectroscopy, and leakage tests. The experimental results showed that GPE devices had much better capacitances and resistances compare to the LE based devices. Moreover, the capacitances of all devices were increased proportionally with the increase in the concentration from 1M to 3M, and the resistances were increased inversely with the decreased of concentration. The promising results from the gel electrolytes is encouraging for further development of flexible and high capacitance energy storage devices.

scholarly journals Constitutive Models for the Prediction of the Hot Deformation Behavior of the 10%Cr Steel Alloy

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2873 ◽  
Author(s):  
Abdallah Shokry ◽  
Samer Gowid ◽  
Ghias Kharmanda ◽  
Elsadig Mahdi
Keyword(s):  
Relative Error ◽  
Hot Deformation ◽  
Mean Squared Error ◽  
Flow Behavior ◽  
Constitutive Models ◽  
Superior Performance ◽  
Steel Alloy ◽  
Statistical Parameters ◽  
Average Absolute Relative Error ◽  
Ann Models

The aim of this paper is to establish a reliable model that provides the best fit to the specific behavior of the flow stresses of the 10%Cr steel alloy at the time of hot deformation. Modified Johnson–Cook and strain-compensated Arrhenius-type (phenomenological models), in addition to two Artificial Neural Network (ANN) models were established with the view toward investigating their stress prediction performances. The ANN models were trained using Scaled Conjugate Gradient (SCG) and Levenberg–Marquardt (LM) algorithms. The prediction accuracy of the established models was evaluated using the following well-known statistical parameters: (a) correlation coefficient (R), (b) Average Absolute Relative Error (AARE), (c) Root Mean Squared Error (RMSE), and Relative Error (RE). The results showed that both of the modified Johnson–Cook and strain-compensated Arrhenius models could not competently predict the flow behavior. On the contrary, the results indicated that the two proposed ANN models precisely predicted the flow stress values and that the LM-trained ANN provided a superior performance over the SCG-trained model, as it yielded an RMSE of as low as 0.441 MPa.

scholarly journals ESTIMATING CAPITAL AND OPERATIONAL COSTS OF BACKHOE SHOVELS

2012 ◽  
Vol 18 (3) ◽  
pp. 378-385 ◽  
Author(s):  
Ahmad Reza Sayadi ◽  
Ali Lashgari ◽  
Mohammad Majid Fouladgar ◽  
Miroslaw J. Skibniewski
Keyword(s):  
Feasibility Study ◽  
Cost Estimation ◽  
Construction Projects ◽  
Cost Model ◽  
Operating Cost ◽  
Principal Component ◽  
Feasibility Studies ◽  
Project Managers ◽  
Cost Models ◽  
Optimum Type

Material loading is one of the most critical operations in earthmoving projects. A number of different equipment is available for loading operations. Project managers should consider different technical and economic issues at the feasibility study stage and try to select the optimum type and size of equipment fleet, regarding the production needs and project specifications. The backhoe shovel is very popular for digging, loading and flattening tasks. Adequate cost estimation is one of the most critical tasks in feasibility studies of equipment fleet selection. This paper presents two different cost models for the preliminary and detailed feasibility study stages. These models estimate the capital and operating cost of backhoe shovels using uni-variable exponential regression (UVER) as well as multi-variable linear regression (MVLR), based on principal component analysis. The UVER cost model is suitable for quick cost estimation at the early stages of project evaluation, while the MVLR cost function, which is more detailed, can be useful for the feasibility study stage. Independent variables of MVLR include bucket size, digging depth, dump height, weight and power. Model evaluations show that these functions could be a credible tool for cost estimations in prefeasibility and feasibility studies of mining and construction projects.

Process Feasibility Study on Thermal-Plasma System for HFC-23 Decomposition

2010 ◽  
Vol 658 ◽  
pp. 137-140
Author(s):  
Joong Kee Lee ◽  
Kyu Young Cho ◽  
Sang Deuk Lee ◽  
Hwa Young Lee ◽  
Won Young Chang ◽  
...  
Keyword(s):  
Co2 Emissions ◽  
Feasibility Study ◽  
Thermal Plasma ◽  
Computational Analysis ◽  
Operating Cost ◽  
Plasma Process ◽  
Plasma System ◽  
Thermal Plasma Process ◽  
Incineration Process ◽  
Energy Balances

A feasibility study on the use of a thermal plasma process for the destruction of HFC-23 is carried out in comparison with an incineration process. The material and energy balances for both processes are calculated using the commercial simulator, Pro/II (ver. 8.0). Based on the computational analysis, the volume of the plasma process and NOx and CO2 emissions in the plasma process are 25, 10 and 40% of those in the incineration process, respectively. Therefore, more compact units can be employed in the plasma process. However, the operating cost of the plasma process would be higher than that of the incineration process using LNG as a fuel.

Wave Rotor Combustor Test Rig Preliminary Design

2004 ◽  
Author(s):  
Berrak Alparslan ◽  
M. Razi Nalim ◽  
Philip H. Snyder
Keyword(s):  
Computational Models ◽  
Combustion Process ◽  
Constant Volume ◽  
Operating Conditions ◽  
Experimental Program ◽  
Preliminary Design ◽  
Wave Rotor ◽  
Test Rig ◽  
Operating Cycle ◽  
And Performance

Pressure gain combustion in a wave rotor approaching the thermodynamic ideal of constant volume combustion has been proposed to significantly enhance the performance of gas turbine engines. A computational and experimental program is currently being conducted to investigate the combustion process and performance of a wave rotor with detonative and near-detonative internal combustion. An innovative and flexible preliminary design of the test rig is presented to demonstrate the operation and performance of the system. A preliminary design method based on a sequence of computational models is used to design wave processes for testing in the rig and to define rig geometry and operating conditions. The operating cycle allows for propagation of the combustion front from the exit end of the combustion channel to the inlet end. This is similar to and motivated by the Constant Volume Combustor (CVC) concept that seeks to produce a relatively uniform set of outflow conditions in both spatial and time coordinates.

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