Your Selections

Water
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Committees

Events

Magazine

 

Analysis of a Coupling System of Aircraft Environmental Control and Fuel Tank Inerting Based on Membrane Separation

Beihang University-Weixing Yuan, Jiaqi Hou
CAPDI-Yan zheng
  • Technical Paper
  • 2019-01-1895
To be published on 2019-09-16 by SAE International in United States
This paper raises a coupling system of aircraft environmental control and fuel tank inerting based on membrane separation. The system applies a membrane dehumidifier to replace water vapor removal unit of heat regenerator, condenser and water separator, which is widely used in conventional aircraft environmental control system nowadays. Water vapor can travel across the membrane wall under its pressure difference without phase change, so the dehumidification process consumes no cooling capacity and the cooling capacity of the system increases. This paper first compares the thermodynamic properties of environmental control system based on membrane dehumidification and the environmental control system based on condensation. The results show that the membrane dehumidification system has bigger cooling capacity and lighter weight. For a given cooling capacity requirement of a certain aircraft, the membrane dehumidification system can use less bleed air since the temperature of the outlet air is lower. Nowadays, the fuel tanking inerting system also uses an air separation module to produce nitrogen enriched air based on membrane separation. After the air is dehumidified in membrane environmental control…
 
new

A Three-Layer Thermodynamic Model for Ice Crystal Accretion on Warm Surfaces: EMM-C

Rolls-Royce Plc-Geoffrey Jones, Benjamin Collier
University of Oxford-Alexander Bucknell, Matthew McGilvray, David Gillespie
Published 2019-06-10 by SAE International in United States
Ingestion of high altitude atmospheric ice particles can be hazardous to gas turbine engines in flight. Ice accretion may occur in the core compression system, leading to blockage of the core gas path, blade damage and/or flameout. Numerous engine powerloss events since 1990 have been attributed to this mechanism. An expansion in engine certification requirements to incorporate ice crystal conditions has spurred efforts to develop analytical models for phenomenon, as a method of demonstrating safe operation. A necessary component of a complete analytical icing model is a thermodynamic accretion model. Continuity and energy balances are performed using the local flow conditions and the mass fluxes of ice and water that are incident on a surface to predict the accretion growth rate. In this paper, a new thermodynamic model for ice crystal accretion is developed through adaptation of the Extended Messinger Model (EMM) from supercooled water conditions to mixed phase conditions (ice crystal and supercooled water). A novel three-layer accretion structure is proposed and the underlying equations described. The EMM improves upon the original model for…
Datasets icon
Annotation icon
 
new

Microwave Technique for Liquid Water Detection in Icing Applications

University of Oxford-Matthew McGilvray, David Gillespie
University of Southern Queensland-John Leis, David Buttsworth, Ramiz Saeed, Khalid Saleh
Published 2019-06-10 by SAE International in United States
The partial melting of ingested ice crystals can lead to ice accretion in aircraft compressors, but accurately measuring the relatively small fraction of liquid water content in such flows is challenging. Probe-based methods for detecting liquid water content are not suitable for deployment within turbofan engines, and thus alternatives are sought. Recent research has described approaches based on passive microwave sensing. We present here an approach based on active microwave transmission and reflection, employing a vector network analyzer. Utilization of both transmission and reflection provides additional data over and above emission or transmission only, and permits a more controllable environment than passive sensing approaches. The paper specifically addresses the question of whether such an approach is viable within the context of representative icing wind tunnel and engine flow conditions. A quasi-thermal equilibrium approach is presented herein to estimate the melting ratio during microwave analysis of samples at 0 °C. Experimental results using microwaves in the 2.45GHz region are presented, and post-processing methods investigated. This is followed by an investigation of detection limits for ice accretion…
Annotation icon
 
new

Type IV Anti-Icing Fluid Subjected to Light Freezing Rain: Visual and Thermal Analysis

UQAC - AMIL-Jean-Denis Brassard, Caroline Laforte, Christophe Volat
Published 2019-06-10 by SAE International in United States
Deicing the aircraft using fluid, prior takeoff is mandatory; since a thin layer of ice or snow can compromise the safety. With the same idea, to use anti-icing fluid during a frozen precipitation to protect the aircraft is also essential. Commercialized anti-icing fluids all pass the process of qualification as described in the SAE documents. One of these documents specifies a set of tests that reproduce freezing precipitation to obtain endurance time and then the holdover timetables. The endurance time is determined by visual inspection: when 30% of the plate is covered with frozen contaminants. With the evolution of technology and the venue of new tools, it may simplify the process, and at least confirm the observations. This paper proposed a thermal and visual analysis of the behavior of a Type IV fluid subjected to light freezing rain. During the precipitation, the plate temperature is measured with thermocouples and recorded using a visual camera and an IR camera. The use the visual camera in conjunction with the IR camera allowed to understand how the water…
Annotation icon
 
new

SLD and Ice Crystal Discrimination with the Optical Ice Detector

Collins Aerospace-Kaare J. Anderson, Mark D. Ray
Published 2019-06-10 by SAE International in United States
In response to new safety regulations regarding aircraft icing, Collins Aerospace has developed and tested an Optical Ice Detector (OID) capable of discriminating among icing conditions appropriate to Appendix C and Appendix O of 14 CFR Part 25 and Appendix D of Part 33. The OID is a short-range, polarimetric lidar that samples the airstream up to ten meters beyond the skin of the aircraft. The intensity and extinction of the backscatter light correlate with bulk properties of the cloud, such as water content and phase. Backscatter scintillation (combined with the outside air temperature from another probe) signals the presence of supercooled large droplets (SLD) within the cloud-a capability incorporated into the OID to meet the requirements of Appendix O.Recent laboratory and flight tests of the Optical Ice Detector have confirmed the efficacy of the OID to discriminate among the various icing conditions. Drizzle-sized droplets, mixed with a small droplet cloud in the Collins Cloud Chamber, appear as scintillations in the lidar signal when it is processed pulse-by-pulse. Averaging the signal over multiple pulses, causes…
Annotation icon
 
new

Simulations of Thin Film Dynamics on a Flat Plate and an Airfoil

Baylor University-Jordan Sakakeeny, Stephen T. McClain, Yue Ling
Published 2019-06-10 by SAE International in United States
The goal of the present study is to investigate the dynamics of a thin water film on a flat plate and an airfoil using direct numerical simulation (DNS). The first case for a wetted flat plate is used to model former experiments and investigate the dynamics of a wind-driven water film. The second case for a thin film on a NACA 0012 airfoil of chord length 0.5 m is used to investigate the dynamics of a wind-driven water film on a curved surface. Particular attention is paid to the interaction between the liquid film and the air shear-layer above the film. As the incoming airflow moves over the thin water film, instability is triggered at the gas-liquid interface. Interfacial waves develop and are advected downstream. The interaction between the air flow and the interfacial waves induces shedding vortices near the interface, which in turn perturb the liquid film farther downstream. Simulations are performed using the open source multiphase flow solvers, Gerris and Basilisk. Both solvers employ a finite-volume approach and the interface is captured using…
Datasets icon
Annotation icon
 
new

Motivation, Development and Verification of a Rapid 3D Lagrangian Impingement Code - Trajectory and Catch 3D+ (TAC3D+)

AeroTex UK-Ian Roberts
Published 2019-06-10 by SAE International in United States
This paper details the motivation, development and validation of a rapid 3D Lagrangian impingement code, Trajectory and Catch 3D+ (TAC3D+). AeroTex’s motivation to develop a 3D Lagrangian method was primarily driven by the inherent mesh dependent dissipation effect found in their 3D Eulerian Water Catch code (EWC) [1]. Studies performed by AeroTex have shown that for geometries where there are aft impingement regions that are partly shadowed by a more forward impingement region, the level of water flux dissipation can be significant, particularly if the mesh is coarse and the impingement region is far aft. Examples of issues where this may be a particular issue would be impingement on a centerline aft mounted engine or the calculation of impingement on the wing root/belly fairing. The code has been developed around a modified version of the OpenFOAM Lagrangian solver. The analysis process consists of three main phases; a coarse droplet trajectory calculation to identify the region of interest, a refined trajectory calculation that is sufficiently fine to calculate local water collection and a surface water collection…
Annotation icon
 
new

Extension of a 2D Algorithm for Catch Efficiency Calculation to Three Dimensions

Airbus-Christian Bartels
FH Joanneum GmbH-Thomas Neubauer, Wolfgang Hassler
Published 2019-06-10 by SAE International in United States
Accurate calculation of the catch efficiency β is of paramount importance for any ice accretion calculation since β is the most important factor in determining the mass of ice accretion. A new scheme has been proposed recently in [1] for accurately calculating β on a discretized two-dimensional geometry based on the results of a Lagrangian droplet trajectory integrator (start and impact conditions).This paper proposes an extension to the algorithm in Ref. [1], which is applicable to three-dimensional surfaces with arbitrary surface discretization. The 3D algorithm maintains the positive attributes of the original 2D algorithm, namely mass conservation of the impinging water, capability to deal with overlapping impingement regions and with crossing trajectories, computational efficiency of the algorithm, and low number of trajectories required to reach good accuracy in catch efficiency. At the same time, the new 3D algorithm avoids typical difficulties of other approaches to determine the catch efficiency β, like noisy β (results varying significantly between neighboring surface cells), catch efficiency of zero for surface cells surrounded by other cells with β > 0,…
Annotation icon
 
new

Uncertainty of the Ice Particles Median Mass Diameters Retrieved from the HAIC-HIWC Dataset: A Study of the Influence of the Mass Retrieval Method

Delphine Leroy
Airbus-Alice Grandin, Fabien Dezitter
Published 2019-06-10 by SAE International in United States
In response to the ice crystal icing hazard identified twenty years ago, aviation industry, regulation authorities, and research centers joined forces into the HAIC-HIWC international collaboration launched in 2012. Two flight campaigns were conducted in the high ice water content areas of tropical mesoscale convective systems in order to characterize this environment conducive to ice crystal icing. Statistics on cloud microphysical properties, such as Ice Water Content (IWC) or Mass Median Diameter (MMD), derived from the dataset of in situ measurements are now being used to support icing certification rulemaking and anti-icing systems design (engine and air data probe) activities. This technical paper focuses on methodological aspects of the derivation of MMD. MMD are estimated from PSD and IWC using a multistep process in which the mass retrieval method is a critical step. Complementary to previous studies reporting on MMD values calculated from the HAIC-HIWC dataset, this paper deals with the uncertainty in MMD by comparing two different approaches for the retrieval of the mass-size (m-D) relationship. The analysis encompasses the data collected in the…
Datasets icon
Annotation icon
 
new

Summary of the High Ice Water Content (HIWC) RADAR Flight Campaigns

AMA-NASA Langley Research Center-Justin Strickland, Patricia Hunt
FAA William J. Hughes Technical Center-Christopher Dumont
Published 2019-06-10 by SAE International in United States
NASA and the FAA conducted two flight campaigns to quantify onboard weather radar measurements with in-situ measurements of high concentrations of ice crystals found in deep convective storms. The ultimate goal of this research was to improve the understanding of high ice water content (HIWC) and develop onboard weather radar processing techniques to detect regions of HIWC ahead of an aircraft to enable tactical avoidance of the potentially hazardous conditions. Both HIWC RADAR campaigns utilized the NASA DC-8 Airborne Science Laboratory equipped with a Honeywell RDR-4000 weather radar and in-situ microphysical instruments to characterize the ice crystal clouds. The purpose of this paper is to summarize how these campaigns were conducted and highlight key results.The first campaign was conducted in August 2015 with a base of operations in Ft. Lauderdale, Florida. Ten research flights were made into deep convective systems that included Mesoscale Convective Systems (MCS) near the Gulf of Mexico and Atlantic Ocean, and Tropical Storms Danny and Erika near the Caribbean Sea. The radar and in-situ measurements from these ten flights were analyzed…
Annotation icon