Commercial Space Operations Noise and Sonic Boom Modeling and Analysis (2018) / Chapter Skim
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From page 8... ...
2-1 CHAPTER 2. Technical Reference 2.1.
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2.1.1. Sou The the rocket 2.1.1 for the sou its total th Ridge Re between f 2014]
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2.1.1 a static en of the rela 2012; Buc rocket exh airflow. C descendin velocity d the differe which red typically g a forward 2.1.1 specific d receiver.
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2.1.1 observer m by the m frequency identical During a sound as explained crest is em slightly le successive source of from the reducing t where a) moving a frequency sound lev frequencie FIGURE for highe velocity < 2.1.2.
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procedure standard. 2.1.2 provide a accurately to ground receiver a ground m energy to Embleton wind and included i ground wh FIGURE 2.1.2.4.
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FIGURE set distan 2-6 Measu ces from th FIGURE red versus p e launch pad 2-7 Measur redicted laun - (right) Ma ed versus pr ch vehicle n ximum OAS edicted laun oise exposur PL at set di ch vehicle no e levels - (le stances from ise time hist ft)
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From page 14... ...
2.2. Soni The [Plotkin e model inc operations C A H B F An e tourism th ship at sl descends down" mo powered a flight dur SpaceShip characteri FIGURE The includes b presented and signa metrics ca 2.2.1.
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the length sketched recompres between. Figu shown at perspectiv perspectiv later time always as associated azimuths.
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Follo crossing a the associ the focus Focal zon properly r booms, bu FIGURE Figu associated moderate steep dive elliptical where des ray cone h vertical la ground un FIGU wing rays is nd tracing o ated isopemp region. Ther es are genera epresent.
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2-10 2.2.1.2. Vehicle Source Characteristics Sonic booms are the wave field of a supersonic vehicle, as heard on the ground.
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2-11 FIGURE 2-17 Logical flow of sonic boom calculations. There are additional elements to sonic boom computation which must be considered under certain circumstances: Prediction and Computation of Focal Zone Signatures.
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2-12 in PCBoom. The main ray tracing and signature aging module, FOBoom, calculates signatures with thin shocks.
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FIGURE N-wav Laun As underexpa F-function parameter 1975] the universal parameter Hyp The Tiegerman It is best u weight an assumes a did not ge 2.2.2.2 P Soni signature propagate is based orthogona tracing yi 2-18 F-fun e, based on s ch Vehicle M part of the nded rocket for the veh s are based ory with dra plume mod s.
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From page 21... ...
Figu cone that independe interest on plane con 1972] calc Acou Cons where P sound spe assumptio The amplitude including substitute phase fun FIGUR re 2-21 illustr is orthogona nt variables: that ray con taining the fl ulated boom stics and th ider a sound trp , r is a spati ed.
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From page 22... ...
2-15 however, the limit is taken, such that the acoustic wavelength is small compared to the gradient scales of unperturbed flow quantities, the following two equations are obtained [Blokhintzev, 1946]
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The diagonally a quantity local unit sectional a Ellip Trad flat Earth where pro gradients. boom car distances examples capability section an scheme th al., 2010]
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point of t sketched i x,y that c offset to t an initial r Schu Beca There are trajectorie Schulten relation fo where q i somewhat and the ra Equa natural ch integratio derivative layered sc surface. G easy to ex he x axis is n Figure 2-2 an be related he ellipsoid)
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From page 25... ...
routines a are compu Prov origins an step sizes Later ellipses si the spatia Admittanc sample ra types of o 2.2.2.3 S As a signatures rather tha the local s Prop where p waveform Figu When a p become si The wave. Wh for weak shock.
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From page 26... ...
2-19 implemented in two steps: an "age parameter" that defines how much the wave has steepened, and a general area balance procedure. The Age Parameter Sonic boom propagation may be summarized by the linear solution [Witham, 1956]
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From page 27... ...
Area A ge [Middleto The key to balance o handling process fo Figu integral o regions. points of o complex Equation equal that shocks wi similar m iterating t Midd integral o where shocks fo it can evo between s intersectio coalescen Haye piecewise the differe Balance an neral signatu n et al., 196 this method f the F-funct multiple cros r its applicat re 2-25 illus f the F-funct Each region verlapping f signatures is (14)
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From page 28... ...
2-21 Fs1 (17) The equivalent of Equation (16)
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2-22 point will thus move in space, and in two dimensions will trace out a line. This line (or surface in three dimensions)
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From page 30... ...
2-23 As noted, Pmax is the traditional measure of the amplitude of N-wave booms. CSEL is specified by standards [ANSI, 1996]
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