Flight Characteristics with Different Supercooled Large Droplet Ice Configurations

An evaluation of the effects of different ice configurations on the flight characteristics of a fixed-wing aircraft is presented. Within a joint research project of German Aerospace Center (DLR) and Brazilian aircraft manufacturer Embraer simulation models of three supercooled large droplet (SLD) ice configurations were developed for one Phenom 300 prototype. A specific flight test campaign with artificial SLD ice shapes on the aircraft was conducted to gather the relevant flight data. The simulation models for the different ice configuration were obtained by system identification, and specific results for the SLD-ice simulation models are provided. The analysis of aircraft characteristics was based on the results of these high-quality simulation models: the icing-induced changes of the flight performance characteristics evaluated by the interpretation of several parameters like thrust-to-weight ratio and specific excess power. The typical flight performance degradation was found for all ice configurations with different magnitude. The change of aircraft eigenmodes was investigated in detail by analysing the system matrix of the linearised models at a specific trim points. In addition, the diverse effects found for different ice configurations (App. C and SLD) are discussed and the change of root locus is analysed. Furthermore, ice-induced changes of the handling qualities are evaluated using numerical criteria of flying qualities standard "MIL-STD-1797 A": no significant deterioration was found for the investigated ice configurations

Testing of an Indirect Ice Detection Methodology in the Horizon2020 Project SENS4ICE

Supercooled large droplets (SLD) icing conditions have been the cause of severe aircraft accidents over the last decades. Existing countermeasures, even on modern airplanes, are not necessarily effective against the resulting ice formations, which raises a demand for reliable detection of SLD and all conditions for safe operations. The EU-funded Horizon 2020 project SENS4ICE focused on new ice detection approaches and innovative sensor hybridization to target a fast and reliable (SLD-)ice detection. The performance-based (indirect) ice detection methodology is key to this approach and based on the changes of airplane flight characteristics under icing influence. This paper provides a short overview of the development and implementation of the indirect ice detection system (IIDS) algorithms in SENS4ICE. Moreover, it gives and discusses first exemplary results from the IIDS tests in classical icing conditions during the SENS4ICE North America flight test campaign conducted in February/March 2023 out of St. Louis Regional Airport in Alton (Illinois, USA)

Comparison of Flight Characteristics of Two Different Airplanes and Ice Configurations

An evaluation of the effects of airframe icing on flight characteristics of fixed-wing aircraft is presented. The analysis is based on high-quality simulation models for different aircraft with distinct wing ice configurations (leading-edge and run-back ice), which are validated with flight test data and CFD results. A comparison of the distinct aerodynamic degradations leads to a general assessment of the icing influences. The icing-induced changes of the flight performance characteristics are revealed due to the interpretation of several parameters like thrust-to-weight ratio, specific excess power or lift-to-drag ratio for each ice configuration and aircraft. The change of aircraft eigenmodes is investigated by analyzing the system matrix of the linearized models at a specific trim point. Furthermore, ice-induced changes of the handling qualities are evaluated using numerical criteria of "MIL-STD-1797 A"

Facing the Challenges of Aircraft Icing

Icing can have hazardous effects on airplane performance characteristics. It can also be a limiting factor for the safe flight envelope. Icing-induced change of the aircraft’s dynamic behavior and potential premature stall raise the need for pilot situational awareness and an adaptation of any aircraft control strategy. During the last decades, various accidents worldwide have shown the severity of icing related degradations as well as pilots’ difficulties to cope with changes in aircraft behavior. One major cause for these accidents was that with rising air traffic, aircraft were increasingly operated in certain icing conditions containing supercooled large water droplets (SLD) against which current aircraft were not protected. The presentation gives an introduction to the phenomenon of aircraft icing and highlights the peculiarities related to SLD in aviation, also with regards to the regulations. Changes of aircraft characteristics, flight dynamics and handling qualities are discussed. Countermeasures and detection technologies are key to safe aircraft operation in these hazardous conditions. An overview of anti-ice and de-icing systems as well as detailed information on recent research activities on robust and reliable ice detection is given.Hamburg Aerospace Lecture Series --- Collection of Presentations --- http://www.AeroLectures.d

Morfometria das células de leydigem catetos (Tayassu tajacu)

Objetivou-se com esta pesquisa determinar o volume total e individual das células de Leydig, o índice leydigossomático e o número de células de Leydig por testículo e por grama de testículo em catetos. Utilizaram-se testículos de 10 catetos sexualmente maturos, destinados ao abate comercial. O volume total e individual das células de Leydig foi 2,02ml e 1202,74 x 10-12ml, respectivamente. O núcleo e o citoplasma ocuparam, respectivamente, 12,3% e 87,7% de cada célula de Leydig. O índice leydigossomático foi de 0,022%, enquanto que o número de células de Leydig por testículo e por grama de testículo foi, respectivamente, 1,7 bilhões e 92,12 milhões de células. Concluiu-se que os parâmetros morfométrios estudados para as células de Leydig de catetos estão inseridos na média relatada para a maioria das espécies de mamíferos.This work aimed to determine total and individual volume of Leydig cells, leydigosomatic index and the number of Leydig cells per testis and per gram of testis in the collared peccary (Tayassu tajacu). Testes were collected from sexually mature collared peccaries, destined for commercial slaughter. Total and individual volumes of Leydig cells were 2.02 ml and 1,202.74 x 10-12 ml, respectively. The leydigosomatic index was 0.022%, and the number of Leydig cell per testis and per gram of testis was 1.7 billion and 92.12 million, respectively. These results show that morphometric characteristics of Leydig cells in collared peccaries are similar to average results observed for most of the mammalian species studied

Clúster De Alta Disponibilidad Con Heartbeat

Un clúster de alta disponibilidad está conformado por dos máquinas de las mismas características, que están totalmente sincronizada y que permiten que el sistema siga funcionando con normalidad. La alta disponibilidad permite que un servicio funcione correctamente ante un fallo de software o hardware. Esta capacidad de los clústeres de restablecer en pocos segundos un servicio, manteniendo la integridad de los datos, permite que en muchos casos los usuarios no tengan por qué notar que se ha producido un problema, cuando una avería de este tipo, en un sistema sin clúster, podría dejarles sin servicio durante horas. En esta guía veremos cómo construir en un ambiente experimental, un clúster de alta disponibilidad mediante la implementación de máquinas virtuales y el servicio de clúster Heartbeat.Un clúster de alta disponibilidad está conformado por dos máquinas de las mismas características, que están totalmente sincronizada y que permiten que el sistema siga funcionando con normalidad. La alta disponibilidad permite que un servicio funcione correctamente ante un fallo de software o hardware. Esta capacidad de los clústeres de restablecer en pocos segundos un servicio, manteniendo la integridad de los datos, permite que en muchos casos los usuarios no tengan por qué notar que se ha producido un problema, cuando una avería de este tipo, en un sistema sin clúster, podría dejarles sin servicio durante horas. En esta guía veremos cómo construir en un ambiente experimental, un clúster de alta disponibilidad mediante la implementación de máquinas virtuales y el servicio de clúster Heartbeat

Parameter Analysis of a Doppler Lidar Sensor For Gust Detection and Load Alleviation

This paper analyzes the performance of Doppler lidar sensors for gust detection and load alleviation purposes w.r.t. selected parameters of the lidar system and the wind reconstruction algorithm. The presented sensitivity studies are the first part of a larger investigation focused on identifying ideal lidar sensor configurations for gust load alleviation. This first study consists of two parts: in the first part, the effect of the measurement geometry is investigated by varying the scan angle, the number of measurements per laser pulse, and the rotational speed of the sensor's line of sight. In the second part, the effect of wind reconstruction parameters is investigated by varying the power aperture product of the lidar and the smoothing parameters of the wind reconstruction process

Análisis de las propiedades mecánicas del ladrillo tipo bloque artesanal de concreto con adición de aserrín granulado Trujillo 2023

En el presente trabajo de investigación titulado “Análisis de las Propiedades Mecánicas del Ladrillo Tipo Bloque Artesanal de Concreto con Aserrín Granulado Trujillo 2023” se investigó el uso del ladrillo con aserrín granulado como material de construcción, ya que esto ayuda en gran parte al medio ambiente. Se planteo como objetivo: Comprobar si es posible la adición de aserrín granulado para fabricar ladrillo tipo bloque artesanal de concreto sin afectar sus propiedades mecánicas Trujillo 2023. Con un enfoque cuantitativo deductivo, según su propósito es básica y aplicada de carácter experimental, la población estimada fue el ladrillo tipo bloque artesanal convencional de concreto para muros de albañilería. Con una muestra serán 100 ladrillos con distintos porcentajes de 0%(patrón), 5%, 10% y 15% de aserrín granulado Para comprobar si es óptimo el uso de aserrín granulado en los ladrillos tipo bloque se hizo los ensayos de resistencia a la compresión, absorción, densidad y variación dimensional en el laboratorio. Cuyos resultados fueron analizados con las normas técnicas peruanas de unidades de albañilería y se comprobó que si es posible la adición de aserrín granulado para elaborar ladrillo tipo bloque de concreto en un 5 % para muros portantes

Retrospective and Recent Examples of Aircraft and Rotorcraft System Identification at DLR

Aircraft system identification has a five-decades-long tradition at German Aerospace Center (DLR). Over the last two decades, the research covered various topics related to system identification of fixed- and rotary-wing aircraft, nonconventional applications and atmospheric effects, the development of new flight-test procedures for system identification purposes, and specific aircraft model enhancements and corresponding parameter estimation. Comprehensive tools were developed that support this research and can be applied to a variety of different problems and types of vehicles. The paper starts with a short description of the different system identification methods used at DLR and the corresponding tools. The discussion of flight-test procedures and maneuver design as well as sensor fusion and flight-path reconstruction provides information on how to optimize the flight tests for system identification and to arrive at a consistent flight-test database. The examples for fixed-wing aircraft provide information on identification including abnormal conditions such as icing and interaction with atmospheric disturbances as well as modeling of structural mechanics and loads. The identification of high-order rotorcraft models that account for rotor and engine dynamics and even structural modes is discussed, and the identification of rotor mast moments as well as the identification of non-physics-based models and their integration into physics-based models are also covered. A final section shows that system identification can also be used to derive models for gyroplanes and parachutes as well as to derive control equivalent turbulence input models and to estimate complex wind field geometries. Thus, a broad overview of possible applications of system identification is given