Chapter 4: Principles of Flight
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Fog and Low Clouds As Troublemakers During Wildfi Res
When Our Heads Are in the Clouds Sometimes water droplets do not freeze in below- Detecting fog from space Up to 60,000 ft (18,000m) freezing temperatures. This happens if they do not have Weather satellites operated by the National Oceanic The fog comes a surface (like a dust particle or an ice crystal) upon and Atmospheric Administration (NOAA) collect data on on little cat feet. which to freeze. This below-freezing liquid water becomes clouds and storms. Cirrus Commercial Jetliner “supercooled.” Then when it touches a surface whose It sits looking (36,000 ft / 11,000m) temperature is below freezing, such as a road or sidewalk, NOAA operates two different types of satellites. over harbor and city Geostationary satellites orbit at about 22,236 miles Breitling Orbiter 3 the water will freeze instantly, making a super-slick icy on silent haunches (34,000 ft / 10,400m) Cirrocumulus coating on whatever it touches. This condition is called (35,786 kilometers) above sea level at the equator. At this and then moves on. Mount Everest (29,035 ft / 8,850m) freezing fog. altitude, the satellite makes one Earth orbit per day, just Carl Sandburg Cirrostratus as Earth rotates once per day. Thus, the satellite seems to 20,000 feet (6,000 m) Cumulonimbus hover over one spot below and keeps its “birds’-eye view” of nearly half the Earth at once. Altocumulus The other type of NOAA satellites are polar satellites. Their orbits pass over, or nearly over, the North and South Clear and cloudy regions over the U.S. -
A Mean-Line Model to Predict the Design Performance of Radial Inflow Turbines in Organic Rankine Cycles
UNIVERSITÀ DEGLI STUDI DI PADOVA DIPARTIMENTO DI INGEGNERIA INDUSTRIALE CORSO DI LAUREA MAGISTRALE IN INGEGNERIA ENERGETICA TECHNISCHE UNIVERSITÄT BERLIN INSTITUT FÜR ENERGIETECHNIK Tesi di Laurea Magistrale in Ingegneria Energetica A MEAN-LINE MODEL TO PREDICT THE DESIGN PERFORMANCE OF RADIAL INFLOW TURBINES IN ORGANIC RANKINE CYCLES Relatori: Prof. Andrea Lazzaretto Prof.ssa Tatjana Morozyuk (Technische Universität Berlin) Correlatore: Ing. Giovanni Manente Laureando: ANDREA PALTRINIERI ANNO ACCADEMICO 2013/2014 ii Abstract This Master Thesis contributes to the knowledge and the optimization of radial inflow turbine for the Organic Rankine Cycles application. A large amount of literature sources is analysed to understand in the better way the context in which this work is located. First of all, the ORC technology is studied, taking care of all the scientific aspects that characterize it: applications, cycle configurations and selection of the optimal working fluids. After that, the focus is pointed on the expanders, as they are the most important components of this kind of power production plants. Nevertheless. Their behaviour is not always wisely considered in an organic vision of the cycle. In fact, it has been noticed that mostly literature concerning the optimization of ORC considers the performances of the expander as a constant, omitting in this way an essential part of the optimisation process. Starting from these observations, in this Master Thesis radial inflow turbines are carefully analysed, performing a theoretical investigation of the achievable performance. Starting from a critical study of publications concerning the design of radial expanders, a theoretical model is proposed. Then, a design procedure of the geometrical and thermo dynamical characteristics of radial inflow turbine operating whit fluid R-245fa is implemented in a Matlab code. -
Sept. 12, 1950 W
Sept. 12, 1950 W. ANGST 2,522,337 MACH METER Filed Dec. 9, 1944 2 Sheets-Sheet. INVENTOR. M/2 2.7aar alwg,57. A77OAMA). Sept. 12, 1950 W. ANGST 2,522,337 MACH METER Filed Dec. 9, 1944 2. Sheets-Sheet 2 N 2 2 %/ NYSASSESSN S2,222,W N N22N \ As I, mtRumaIII-m- III It's EARAs i RNSITIE, 2 72/ INVENTOR, M247 aeawosz. "/m2.ATTORNEY. Patented Sept. 12, 1950 2,522,337 UNITED STATES ; :PATENT OFFICE 2,522,337 MACH METER Walter Angst, Manhasset, N. Y., assignor to Square D Company, Detroit, Mich., a corpora tion of Michigan Application December 9, 1944, Serial No. 567,431 3 Claims. (Cl. 73-182). is 2 This invention relates to a Mach meter for air plurality of posts 8. Upon one of the posts 8 are craft for indicating the ratio of the true airspeed mounted a pair of serially connected aneroid cap of the craft to the speed of sound in the medium sules 9 and upon another of the posts 8 is in which the aircraft is traveling and the object mounted a diaphragm capsuler it. The aneroid of the invention is the provision of an instrument s: capsules 9 are sealed and the interior of the cas-l of this type for indicating the Mach number of an . ing is placed in communication with the static aircraft in fight. opening of a Pitot static tube through an opening The maximum safe Mach number of any air in the casing, not shown. The interior of the dia craft is the value of the ratio of true airspeed to phragm capsule is connected through the tub the speed of sound at which the laminar flow of ing 2 to the Pitot or pressure opening of the Pitot air over the wings fails and shock Waves are en static tube through the opening 3 in the back countered. -
Multimedia Foundations Glossary of Terms Chapter 8 – Text
Multimedia Foundations Glossary of Terms Chapter 8 – Text Ascender Any part of a lowercase character that extends above the x-height, such as in the vertical stem of the letter b or h. Baseline And imaginary plane where the bottom edge of each character’s main body rests. Baseline Shift Refers to shifting the base of certain characters (up or down) to a new position. Capline An imaginary line denoting the tops of uppercase letters. Counter The enclosed or partially enclosed open area in letters such as O and G. Descender Any part of a character that extends below the baseline; such as in the bottom stroke of a y or p. Flush Left The alignment of text along a common left-edged line. Font Family A collection of related fonts – all of the bolds, italics, and so forth, in their various sizes. Gridline A matrix of evenly spaced vertical and horizontal lines that are superimposed overtop of the design window as a visual aid for aligning objects. Justification The term used when both the left and right edges of a paragraph are vertically aligned. Kerning A technique that selectively varies the amount of space between a single pair of letters and accounts for letter shape; allowing letters like A and V to extend into one another’s virtual blocks. Leading A term used to define the amount of space between vertically adjacent lines of text. Legibility Refers to a typeface’s characteristics and can change depending on font size. The more legible a typeface, the easier it is at a glance to distinguish and identify letters, numbers, and symbols. -
Soaring Weather
Chapter 16 SOARING WEATHER While horse racing may be the "Sport of Kings," of the craft depends on the weather and the skill soaring may be considered the "King of Sports." of the pilot. Forward thrust comes from gliding Soaring bears the relationship to flying that sailing downward relative to the air the same as thrust bears to power boating. Soaring has made notable is developed in a power-off glide by a conven contributions to meteorology. For example, soar tional aircraft. Therefore, to gain or maintain ing pilots have probed thunderstorms and moun altitude, the soaring pilot must rely on upward tain waves with findings that have made flying motion of the air. safer for all pilots. However, soaring is primarily To a sailplane pilot, "lift" means the rate of recreational. climb he can achieve in an up-current, while "sink" A sailplane must have auxiliary power to be denotes his rate of descent in a downdraft or in come airborne such as a winch, a ground tow, or neutral air. "Zero sink" means that upward cur a tow by a powered aircraft. Once the sailcraft is rents are just strong enough to enable him to hold airborne and the tow cable released, performance altitude but not to climb. Sailplanes are highly 171 r efficient machines; a sink rate of a mere 2 feet per second. There is no point in trying to soar until second provides an airspeed of about 40 knots, and weather conditions favor vertical speeds greater a sink rate of 6 feet per second gives an airspeed than the minimum sink rate of the aircraft. -
Technology for Pressure-Instrumented Thin Airfoil Models
NASA-CR-3891 19850015493 NASA Contractor Report 3891 i 1 Technology for Pressure-Instrumented Thin Airfoil Models David A. Wigley ., ..... " .... _' /, !..... .,L_. '' CONTRACT NAS1-17571 MAY 1985 ( • " " c _J ._._l._,.. ¸_ - j, ;_.. , r_ '._:i , _ . ; . ,. NIA NASA Contractor Report 3891 Technology for Pressure-Instrumented Thin Airfoil Models David A. Wigley Applied Cryogenics & Materials Consultants, Inc. New Castle, Delaware Prepared for Langley Research Center under Contract NAS1-17571 N//X National Aeronautics and Space Administration Scientific and Technical InformationBranch 1985 Use of trademarks or names of manufacturers in this report does not constitute an official endorsement of such products or manufacturers, either expressed or implied, by the National Aeronautics and Space Administration. FINAL REPORT ON PHASE 1 OF NASA CONTRACT NASI-17571 "TECHNOLOGY FOR PRESSURE-INSTRUMENTED THIN AIRFOIL MODELS" PROJECT SU_IARY The objective of Phase 1 of this research was to identify, then select and evaluate, the most appropriate combination of materials and fabrication techniques required to produce a Pressure Instrumented Thin Airfoil model for testing in a Cryogenic wind Tunnel ( PITACT ). Particular attention was to be given to proving the feasability and reliability of each sub-stage and ensuring that they could be combined together without compromising the quality of the resultant segment or model. In order to provide a sharp focus for this research, experimental samples were to be fabricated as if they were trailing edge segments of a 6% thick supercritical airfoil, number 0631X7, scaled to a 325mm (13in.) chord, the maximum likely to be tested in the 13in. x 13in. adaptive wall test section of the 0.3m Transonic Cryogenic Tunnel at NASA Langley Research Center. -
Air Pressure
Name ____________________________________ Date __________ Class ___________________ SECTION 15-3 SECTION SUMMARY Air Pressure Guide for ir consists of atoms and molecules that have mass. Therefore, air has Reading A mass. Because air has mass, it also has other properties, includ- ing density and pressure. The amount of mass per unit volume of a N What are some of substance is called the density of the substance. The force per unit area the properties of air? is called pressure. Air pressure is the result of the weight of a column of N What instruments air pushing down on an area. The molecules in air push in all directions. are used to mea- This is why air pressure doesn’t crush objects. sure air pressure? Falling air pressure usually indicates that a storm is approaching. Rising N How does increas- air pressure usually means that the weather is clearing. A ing altitude affect barometer is an instrument that measures changes in air pressure. There air pressure and are two kinds of barometers: mercury barometers and aneroid density? barometers. A mercury barometer consists of a glass tube open at the bottom end and partially filled with mercury. The open end of the tube rests in a dish of mercury, and the space above the mercury in the tube contains no air. The air pressure pushing down on the surface of the mer- cury in the dish is equal to the weight of the column of mercury in the tube. At sea level, the mercury column is about 76 centimeters high, on average. An aneroid barometer has an airtight metal chamber that is sen- sitive to changes in air pressure. -
No Acoustical Change” for Propeller-Driven Small Airplanes and Commuter Category Airplanes
4/15/03 AC 36-4C Appendix 4 Appendix 4 EQUIVALENT PROCEDURES AND DEMONSTRATING "NO ACOUSTICAL CHANGE” FOR PROPELLER-DRIVEN SMALL AIRPLANES AND COMMUTER CATEGORY AIRPLANES 1. Equivalent Procedures Equivalent Procedures, as referred to in this AC, are aircraft measurement, flight test, analytical or evaluation methods that differ from the methods specified in the text of part 36 Appendices A and B, but yield essentially the same noise levels. Equivalent procedures must be approved by the FAA. Equivalent procedures provide some flexibility for the applicant in conducting noise certification, and may be approved for the convenience of an applicant in conducting measurements that are not strictly in accordance with the 14 CFR part 36 procedures, or when a departure from the specifics of part 36 is necessitated by field conditions. The FAA’s Office of Environment and Energy (AEE) must approve all new equivalent procedures. Subsequent use of previously approved equivalent procedures such as flight intercept typically do not need FAA approval. 2. Acoustical Changes An acoustical change in the type design of an airplane is defined in 14 CFR section 21.93(b) as any voluntary change in the type design of an airplane which may increase its noise level; note that a change in design that decreases its noise level is not an acoustical change in terms of the rule. This definition in section 21.93(b) differs from an earlier definition that applied to propeller-driven small airplanes certificated under 14 CFR part 36 Appendix F. In the earlier definition, acoustical changes were restricted to (i) any change or removal of a muffler or other component of an exhaust system designed for noise control, or (ii) any change to an engine or propeller installation which would increase maximum continuous power or propeller tip speed. -
Chapter 7: Stability and Cloud Development
Chapter 7: Stability and Cloud Development A parcel of air: Air inside can freely expand or contract, but heat and air molecules do not cross boundary. A rising parcel of air expands because the air pressure falls with elevation. This expansion causes cooling: (Adiabatic cooling) V V V-2v V v Wall Stationary Wall Moving Away An air molecule that strikes an expanding wall will lose speed on bouncing off wall (temperature of air will fall) V V+2v v Wall Moving Toward A falling parcel of air contracts because it encounters higher pressure. This falling air heats up because of compression. Stability: If rising air cools more quickly due to expansion than the environmental lapse rate, it will be denser than its surroundings and tend to fall back down. 10°C Definitions: Dry adiabatic rate = 1000 m 10°C Moist adiabatic rate : smaller than because of release of latent heat during 1000 m condensation (use 6° C per 1000m for average) Rising air that cools past dew point will not cool as quickly because of latent heat of condensation. Same compensating effect for saturated, falling air : evaporative cooling from water droplets evaporating reduces heating due to compression. Summary: Rising air expands & cools Falling air contracts & warms 10°C Unsaturated air cools as it rises at the dry adiabatic rate (~ ) 1000 m 6°C Saturated air cools at a lower rate, ~ , because condensing water vapor heats air. 1000 m This is moist adiabatic rate. Environmental lapse rate is rate that air temperature falls as you go up in altitude in the troposphere. -
Aviation Glossary
AVIATION GLOSSARY 100-hour inspection – A complete inspection of an aircraft operated for hire required after every 100 hours of operation. It is identical to an annual inspection but may be performed by any certified Airframe and Powerplant mechanic. Absolute altitude – The vertical distance of an aircraft above the terrain. AD - See Airworthiness Directive. ADC – See Air Data Computer. ADF - See Automatic Direction Finder. Adverse yaw - A flight condition in which the nose of an aircraft tends to turn away from the intended direction of turn. Aeronautical Information Manual (AIM) – A primary FAA publication whose purpose is to instruct airmen about operating in the National Airspace System of the U.S. A/FD – See Airport/Facility Directory. AHRS – See Attitude Heading Reference System. Ailerons – A primary flight control surface mounted on the trailing edge of an airplane wing, near the tip. AIM – See Aeronautical Information Manual. Air data computer (ADC) – The system that receives and processes pitot pressure, static pressure, and temperature to present precise information in the cockpit such as altitude, indicated airspeed, true airspeed, vertical speed, wind direction and velocity, and air temperature. Airfoil – Any surface designed to obtain a useful reaction, or lift, from air passing over it. Airmen’s Meteorological Information (AIRMET) - Issued to advise pilots of significant weather, but describes conditions with lower intensities than SIGMETs. AIRMET – See Airmen’s Meteorological Information. Airport/Facility Directory (A/FD) – An FAA publication containing information on all airports, seaplane bases and heliports open to the public as well as communications data, navigational facilities and some procedures and special notices. -
Density Altitude
Federal Aviation Administration Density Altitude FAA–P–8740–2 • AFS–8 (2008) HQ-08561 Density Altitude Note: This document was adapted from the original Pamphlet P-8740-2 on density altitude. Introduction Although density altitude is not a common subject for “hangar flying” discussions, pilots need to understand this topic. Density altitude has a significant (and inescapable) influence on aircraft and engine performance, so every pilot needs to thoroughly understand its effects. Hot, high, and humid weather conditions can cause a routine takeoff or landing to become an accident in less time than it takes to tell about it. Density Altitude Defined Types of Altitude Pilots sometimes confuse the term “density altitude” with other definitions of altitude. To review, here are some types of altitude: • Indicated Altitude is the altitude shown on the altimeter. • True Altitude is height above mean sea level (MSL). • Absolute Altitude is height above ground level (AGL). • Pressure Altitude is the indicated altitude when an altimeter is set to 29.92 in Hg (1013 hPa in other parts of the world). It is primarily used in aircraft performance calculations and in high-altitude flight. • Density Altitude is formally defined as “pressure altitude corrected for nonstandard temperature variations.” Why Does Density Altitude Matter? High Density Altitude = Decreased Performance The formal definition of density altitude is certainly correct, but the important thing to understand is that density altitude is an indicator of aircraft performance. The term comes from the fact that the density of the air decreases with altitude. A “high” density altitude means that air density is reduced, which has an adverse impact on aircraft performance. -
Effect of Tropospheric Air Density and Dew Point Temperature on Radio (Electromagnetic) Waves and Air Radio Wave Refractivity
International Journal of Scientific & Engineering Research, Volume 7, Issue 6, June-2016 356 ISSN 2229-5518 Effect of Tropospheric Air density and dew point temperature on Radio (Electromagnetic) waves and Air radio wave refractivity <Joseph Amajama> University of Calabar, Department of Physics, Electronics and Computer Technology Unit Etta-agbor, Calabar, Nigeria [email protected] Abstract: Signal strengths measurements were obtained half hourly for some hours and simultaneously, the atmospheric components: atmospheric temperature, atmospheric pressure, relative humidity and wind direction and speed were registered to erect the effects of air density and dew point temperature on radio signals (electromagnetic waves) as they travel through the atmosphere and air radio wave refractivity. The signal strength from Cross River State Broadcasting Co-operation Television (CRBC-TV), (4057'54.7''N, 8019'43.7''E) transmitted at 35mdB and 519.25 MHz (UHF) were measured using a Cable TV analyzer in a residence along Ettaabgor, Calabar, Nigeria (4057'31.7''N, 8020'49.7''E) using the digital Community – Access (Cable) Television (CATV) analyzer with 24 channels, spectrum 46 – 870 MHz, connected to a domestic receiver antenna of height 4.23 m. Results show that: on the condition that the wind speed and direction are the same or (0 mph NA), the radio signal strength is near negligibly directly proportional to the air density, mathematically Ss / ∂a1.3029 = K, where Ss is Signal Strength in dB, ∂a is Density of air Kg/m3 and K is constant; radio