scholarly journals Data-Driven Modeling of Fuel Consumption for Turboprop-Powered Civil Airliners

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1695
Author(s):  
Benoit G. Marinus ◽  
Antoine Hauglustaine

Next to empirical correlations for the specific range, fuel flow rate, and specific fuel consumption, a response surface model for estimates of the fuel consumption in early design stages is presented and validated. The response-surface’s coefficients are themselves predicted from empirical correlations based solely on the operating empty weight. The model and correlations are all derived from fuel consumption data of nine current civil turbo-propeller aircraft and are validated on a separate set. The model can accurately predict fuel weights of new designs for any combination of payload and range within the current range of efficiency of the propulsion. The accuracy of the model makes it suited for preliminary and conceptual design of near-in-kind turbo-propeller aircraft. The model can shorten the design cycle by delivering fast and accurate fuel weight estimates from the first design iteration once the operating empty weight is known. Since it is based solely on the operating empty weight and it is accurate, the model is a sound variant to the Breguet range equation in order to make accurate fuel weight estimates.

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ali Dinc ◽  
Yousef Gharbia

Abstract In this study, exergy efficiency calculations of a turboprop engine were performed together with main performance parameters such as shaft power, specific fuel consumption, fuel flow, thermal efficiency etc., for a range of flight altitude (0–14 km) and flight speeds (0–0.6 Mach). A novel exergy efficiency formula was derived in terms of specific fuel consumption and it is shown that these two parameters are inversely proportional to each other. Moreover, a novel exergy efficiency and thermal efficiency relation was also derived. The relationship showed that these two parameters are linearly proportional to each other. Exergy efficiency of the turboprop engine was found to be in the range of 23–33%. Thermal efficiency of the turboprop engine was found to be around 25–35%. Exergy efficiency is higher at higher speeds and altitude where the specific fuel consumption is lower. Conversely, exergy efficiency of the engine is lower for lower speeds and altitude where the specific fuel consumption is higher.


2021 ◽  
Vol 13 (14) ◽  
pp. 8066
Author(s):  
Thowayeb H. Hassan ◽  
Abu Elnasr E. Sobaih ◽  
Amany E. Salem

The cost of fuel and its availability are among the most major concerns for aircrafts and the aviation industry overall. Environmental difficulties with chemical pollutant emissions emitted by aviation machines are also connected to fuel consumption. As a result, it is crucial to examine factors that affect the overall fuel usage and consumption in the airport-based aviation industry. Several variables were investigated related to the total fuel consumed, such as dry operating weight (DOW) (KG), zero-fuel weight (ZFW), take-off weight (TOW), air distance (AIR DIST) (KM), and ground distance (GDN DIST). Analysis of the correlation between total fuel consumed as well as the extra fuel and selected variables was conducted. The results showed that the most positively associated factors with the total used fuel were the air distance (r2 = 0.86, p < 0.01), ground distance (r2 = 0.78, p < 0.01), TOW (r2 = 0.68, p < 0.01), and flight time (r2 = 0.68, p < 0.01). There was also a strong positive association between the average fuel flow (FF) and actual TOW (r2 = 0.74, p < 0.01) as well as ZFW (r2 = 0.61, p < 0.01). The generalized linear model (GLM) was utilized to assess the predictions of total energy usage after evaluating important outliers, stability of the homogeneity of variance, and the normalization of the parameter estimation. The results of multiple linear regression revealed that the most significant predictors of the total consumed fuel were the actual ZFW (p < 0.01), actual TOW (p < 0.01), and actual average FF (p < 0.05). The results interestingly confirmed that wind speed has some consequences and effects on arrival fuel usage. The result reflects that thermal and hydrodynamic economies impact on the flying fuel economy. The research has various implications for both scholars and practitioners of aviation industry.


Author(s):  
B. A. Haberman ◽  
A. J. Marquis

A typical segmented-in-series tubular solid oxide fuel cell (SOFC) consists of flattened ceramic support tubes with rows of electrochemical cells fabricated on their outer surfaces connected in series. It is desirable to design this type of SOFC to operate with a uniform electrolyte current density distribution to make the most efficient use of the available space and possibly to help minimize the onset of cell component degradation. Predicting the electrolyte current density distribution requires an understanding of the many physical and electrochemical processes occurring, and these are simulated using the newly developed SOHAB multiphysics computer code. Of particular interest is the interaction between the current flow within the cells and the consumption of fuel from an adjacent internal gas supply channel. Initial simulations showed that in the absence of fuel consumption, ionic current tends to concentrate near the leading edge of each electrolyte. Further simulations that included fuel consumption showed that the choice of fuel flow direction can have a strong effect on the current flow distribution. The electrolyte current density distribution is biased toward the upstream fuel flow direction because ionic current preferentially flows in regions rich in fuel. Thus the correct choice of fuel flow direction can lead to more uniform electrolyte current density distributions, and hence it is an important design consideration for tubular segmented-in-series SOFCs. Overall, it was found that the choice of fuel flow direction has a negligible effect on the output voltage of the fuel cells.


Author(s):  
Alejandro Briones ◽  
Andrew W Caswell ◽  
Brent Rankin

Abstract This work presents fully-coupled computational fluid dynamic (CFD) simulations and thermodynamic cycle analyses of a small-scale turbojet engine at several conditions along the equilibrium running line. The CFD simulations use a single mesh for the entire engine, from the intake to the exhaust, allowing information to travel in all directions. The CFD simulations are performed along the equilibrium running line by using the iterative Secant method to compute the fuel flow rate required to match the compressor and turbine power. The freestream pressure and temperature and shaft angular speed are the only inputs needed for the CFD simulations. To evaluate the consistency of the CFD results with thermodynamic cycle results, outputs from the CFD simulations are prescribed as inputs to the cycle model. This approach enables on-design and off-design cycle calculations to be performed without requiring turbomachinery performance maps. In contrast, traditional off-design cycle analyses require either scaling, calculating, or measuring compressor and turbine maps with boundary condition assumptions. In addition, the CFD simulations and the cycle analyses are compared with measurements of the turbojet engine. The CFD simulations, thermodynamic cycle analyses, and measurements agree in terms of total temperature and pressure at the diffuser-combustor interface, air and fuel mass flow rate, equivalence ratio, and thrust. The developed methods to perform CFD simulations from the intake to the exhaust of the turbojet engine are expected to be useful for guiding the design and development of future small-scale gas turbine engines.


1986 ◽  
Vol 10 (1) ◽  
pp. 10-15 ◽  
Author(s):  
Dennis A. Werblow ◽  
Frederick W. Cubbage

Abstract Forest harvesting equipment purchase costs in 1984 were determined by a survey of equipment dealers and manufacturers operating in the South. Based on delivered purchase prices, fixed costs for equipment ownership were calculated using machine rate formulas. Equipment operating costs were estimated based on general guidelines, fuel consumption data, and historical records. The fixed and operating cost data can be used when considering equipment investments and analyzing actual or potential harvesting systems.


Author(s):  
Colin Rodgers ◽  
Aubrey Stone

The partload fuel consumption characteristics of single and, two shaft recuperated, and two spool intercooled recuperative small 300 kw class gas turbines were studied in order to compare with an advanced diesel engine. With variable speed and either constant turbine inlet temperature or constant turbine exhaust temperature these three engines were judged to potentially possess a normalized fuel consumption versus load characteristic comparing favorably with that of a Diesel engine. This is moreover without the complications of many past patented Brayton cycle novel concepts conceived to achieve nearly constant thermal efficiency. Fundamentally part load optimization for a specific gas turbine engine focuses upon the slope of its fuel consumption versus power from the design point to the idle condition. The idle condition is typically set by a specified accessory load above that of the no load, or self sustaining speed, and or lean blow out limit of the combustor. It is shown that although this fuel flow slope can be slightly changed with component efficiency fall off characteristics, or with dual engine packs, for a single engine it is dominated by the two end points, the design and no load fuel flows. The premise that such 300 kw class gas turbines could however challenge the manufacturing, and direct operating costs of an advanced technology Diesel engine, besides meeting future emissions regulations remains to be aggressively pursued.


Author(s):  
Yashovardhan S. Chati ◽  
Hamsa Balakrishnan

Fuel burn is a key driver of aircraft performance, and contributes to airline costs and emissions. Low-altitude fuel burn and emissions, such as those that occur during climb out and approach, have a significant impact on the environment in the vicinity of airports. This paper proposes a new methodology to statistically model fuel burn in the climb out and approach phases using the trajectory of an aircraft. The model features are chosen by leveraging a physical understanding of aircraft and engine dynamics. Model development is conducted through the use of Gaussian Process Regression on a limited Flight Data Recorder archive, which also provides ground truth estimates of the fuel flow rate and total fuel burn. The result is a class of models that provide predictive distributions of the fuel burn corresponding to a given aircraft trajectory, thereby also quantifying the uncertainty in the predictions. The performance of the proposed models is compared with other frequently used Aircraft Performance Models. The statistical models are found to reduce the error in the estimated total fuel burn by more than 73% in climb out and by 59% in approach.


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