6 research outputs found
A new aircraft architecture based on the ACHEON Coanda effect nozzle: flight model and energy evaluation
Purpose
Aeronautic transport has an effective necessity of reducing fuel consumption and emissions to deliver efficiency and competitiveness driven by today commercial and legislative requirements. Actual aircraft configurations scenario allows envisaging the signs of a diffused technological maturity and they seem very near their limits. This scenario clearly shows the necessity of radical innovations with particular reference to propulsion systems and to aircraft architecture consequently.
Methods
This paper presents analyses and discusses a promising propulsive architecture based on an innovative nozzle, which allows realizing the selective adhesion of two impinging streams to two facing jets to two facing Coanda surfaces. This propulsion system is known with the acronym ACHEON (Aerial Coanda High Efficiency Orienting Nozzle). This paper investigates how the application of an all-electric ACHEONs propulsion system to a very traditional commuter aircraft can improve its relevant performances. This paper considers the constraints imposed by current state-of-the-art electric motors, drives, storage and conversion systems in terms of both power/energy density and performance and considers two different aircraft configurations: one using battery only and one adopting a more sophisticated hybrid cogeneration. The necessity of producing a very solid analysis has forced to limit the deflection of the jet in a very conservative range (±15°) with respect to the horizontal. This range can be surely produced also by not optimal configurations and allow minimizing the use of DBD. From the study of general flight dynamics equations of the aircraft in two-dimensional form it has been possible to determine with a high level of accuracy the advantages that ACHEON brings in terms of reduced stall speed and of reduced take-off and landing distances. Additionally, it includes an effective energy analysis focusing on the efficiency and environmental advantages of the electric ACHEON based propulsion by assuming the today industrial grade high capacity batteries with a power density of 207 Wh/kg.
Results
It has been clearly demonstrated that a short flight could be possible adopting battery energy storage, and longer duration could be possible by adopting a more sophisticated cogeneration system, which is based on cogeneration from a well-known turboprop, which is mostly used in helicopter propulsion. This electric generation system can be empowered by recovering the heat and using it to increase the temperature of the jet. It is possible to transfer this considerable amount of heat to the jet by convection and direct fluid mixing. In this way, it is possible to increase the energy of the jets of an amount that allows more than recover the pressure losses in the straitening section. In this case, it is then possible to demonstrate an adequate autonomy of flight and operative range of the aircraft. The proposed architecture, which is within the limits of the most conservative results obtained, demonstrates significant additional benefits for aircraft manoeuvrability. In conclusion, this paper has presented the implantation of ACHEON on well-known traditional aircraft, verifying the suitability and effectiveness of the proposed system both in terms of endurance with a cogeneration architecture and in terms of manoeuvrability. It has demonstrated the potential of the system in terms of both takeoff and landing space requirements.
Conclusions
This innovation opens interesting perspectives for the future implementation of this new vector and thrust propulsion system, especially in the area of greening the aeronautic sector. It has also demonstrated that ACHEON has the potential of renovating completely a classic old aircraft configuration such as the one of Cessna 402
Acheon Project: a novel vectoring jet concept
This paper presents a general overview of the Acheon Project (EU FP7 Level 0 - Transport including Aeronautic). This project present a novel dynamically controllable Coanda jet using two fluid streams to produce the angular deflection of the jet as a function of their momentum. A control system by eloctrostatic plasma is used to produce an effective and more precise control of the system. This paper presents the general guidelines of the project which is going to start and presents expected result
Validity of bioelectrical impedance analysis to estimation fat-free mass in the army cadets
Bioelectrical Impedance Analysis (BIA) is a fast, practical, non-invasive, and frequently used method for fat-free mass (FFM) estimation. The aims of this study were to validate predictive equations of BIA to FFM estimation in Army cadets and to develop and validate a specific BIA equation for this population. Methods: A total of 396 males, Brazilian Army cadets, aged 17â24 years were included. The study used eight published predictive BIA equations, a specific equation in FFM estimation, and dual-energy X-ray absorptiometry (DXA) as a reference method. Studentâs t-test (for paired sample), linear regression analysis, and BlandâAltman method were used to test the validity of the BIA equations. Results: Predictive BIA equations showed significant differences in FFM compared to DXA (p < 0.05) and large limits of agreement by BlandâAltman. Predictive BIA equations explained 68% to 88% of FFM variance. Specific BIA equations showed no significant differences in FFM, compared to DXA values. Conclusion: Published BIA predictive equations showed poor accuracy in this sample. The specific BIA equations, developed in this study, demonstrated validity for this sample, although should be used with caution in samples with a large range of FFM.83COORDENAĂĂO DE APERFEIĂOAMENTO DE PESSOAL DE NĂVEL SUPERIOR - CAPESFUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULO - FAPESP23001.000422/98-302011/23460-
Validity of Bioelectrical Impedance Analysis to Estimation Fat-Free Mass in the Army Cadets
Background: Bioelectrical Impedance Analysis (BIA) is a fast, practical, non-invasive, and frequently used method for fat-free mass (FFM) estimation. The aims of this study were to validate predictive equations of BIA to FFM estimation in Army cadets and to develop and validate a specific BIA equation for this population. Methods: A total of 396 males, Brazilian Army cadets, aged 17â24 years were included. The study used eight published predictive BIA equations, a specific equation in FFM estimation, and dual-energy X-ray absorptiometry (DXA) as a reference method. Studentâs t-test (for paired sample), linear regression analysis, and BlandâAltman method were used to test the validity of the BIA equations. Results: Predictive BIA equations showed significant differences in FFM compared to DXA (p < 0.05) and large limits of agreement by BlandâAltman. Predictive BIA equations explained 68% to 88% of FFM variance. Specific BIA equations showed no significant differences in FFM, compared to DXA values. Conclusion: Published BIA predictive equations showed poor accuracy in this sample. The specific BIA equations, developed in this study, demonstrated validity for this sample, although should be used with caution in samples with a large range of FFM
Physical training over 6 months is associated with improved changes in phase angle, body composition, and blood glucose in healthy young males
The aim of this study was to evaluate the association between phase angle, body composition, and blood glucose changes in healthy young males after 6 months of physical training. Methods Volunteers, 98 healthy males (18.8 +/- 0.5 years), had 6 months of progressive physical training (5 days a week, 90 minutes a day). Resistance, reactance, and phase angle were obtained by bioelectrical impedance analysis, body composition (fat mass, bone mineral content [BMC], and lean soft tissue [LST]) by dual-energy X-ray absorptiometry, and blood glucose by reflectance photometry. Measurements were made at rest and in a fasted state, both before and after the training period. Results Phase angle, reactance, BMC, and LST significantly increased (0.6 degrees, 3.8 omega, 0.1 kg, and 1.9 kg, respectively; P < .01), whereas resistance and blood glucose decreased (-11.2 omega and -4.1 mg/dL; P < .01). Changes in resistance and reactance explained those changes observed in LST (R-2 = .26 and .16, respectively), but phase angle changes were not related to body composition and blood glucose alterations (P < .05). Conclusions A 6-month period of physical training was associated with positive changes in phase angle, body composition, and blood glucose in healthy young males, reinforcing the importance of maintaining a physically active lifestyle.315CAPES - Coordenação de Aperfeiçoamento de Pessoal e NĂvel Superior23001.000422/98-3
Effect of Physical Training on Body Composition in Brazilian Military
The military are selected on the basis of physical standards and are regularly involved in strong physical activities, also related to particular sports training. The aims of the study were to analyze the effect of a 7-month military training program on body composition variables and the suitability of specific ‘bioelectrical impedance vector analysis’ (spBIVA), compared to DXA, to detect the changes in body composition. A sample of 270 male Brazilian cadets (19.1 ± 1.1 years), composed of a group practicing military physical training routine only (MT = 155) and a group involved in a specific sport training (SMT = 115), were measured by body composition assessments (evaluated by means of DXA and spBIVA) at the beginning and the end of the military routine year. The effect of training on body composition was similar in SMT and MT groups, with an increase in LST. DXA and spBIVA were correlated, with specific resistance (Rsp) and reactance (Xcsp) positively related to fat mass (FM), FM%, LST, and lean soft tissue index (LSTI), and phase angle positively related to LST and LSTI. Body composition variations due to physical training were recognized by spBIVA: the increase in muscle mass was indicated by the phase angle and Xcsp increase, and the stability of FM% was consistent with the unchanged values of Rsp. Military training produced an increase in muscle mass, but no change in FM%, independently of the sample characteristics at baseline and the practice of additional sports. SpBIVA is a suitable technique for the assessment of body composition in military people