Experimental Investigation of the Starting Behavior of a Three-Dimensional Scramjet Intake

Flock, Andreas K.; Gülhan, Ali

doi:10.2514/1.j053786

Cited by 26 publications

(14 citation statements)

References 16 publications

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“…In a previous study, we performed starting experiments in a hypersonic blowdown wind tunnel, known as H2K, at the German Aerospace Center (DLR) in Cologne with a three-dimensional intake model [4,14], and we complemented the analysis with CFD [15]. The model was equipped with a movable cowl, permitting variable internal contraction so that, during an experiment, the CR i was slowly decreased until intake starting occurred.…”

Section: A Literature Reviewmentioning

confidence: 99%

“…As we described in a previous study [4] for an arbitrary intake diffuser, there are two equations that relate the Mach number to the contraction ratio: First, isentropic compression to sonic flow at the intake throat limits the intake's contraction ratio to a maximum for a given Mach number:…”

mentioning

confidence: 99%

“…Other parameters such as the Reynolds number [8], the total freestream-to-wall temperature ratio [4], or the boundary-layer thickness [9] were reported to have minor influences on intake starting.…”

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confidence: 99%

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Modified Kantrowitz Starting Criteria for Mixed Compression Supersonic Intakes

Flock

Gülhan

2019

AIAA Journal

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A proper understanding of the intake starting process of supersonic airbreathing engines is crucial for a successful operation of the supersonic aircraft, especially for three-dimensional geometries in which no reliable starting prediction for a broad Mach number range exists, and the widespread Kantrowitz criterion only provides a conservative prediction. Experimental investigations from the literature are reviewed and put into the perspective of the Kantrowitz theory. First, an empirical relation is developed that is valid for a wide Mach number range, and that can be calibrated to certain classes of intakes by the user. Second, the Kantrowitz assumptions are modified and a semiempirical relation is derived. The semiempirical relation turned out to be an optimistic limit for self-starting. NomenclatureA = area, m 2 a = speed of sound, m∕s C 1 = constant h = specific enthalpy, J∕kg k = constant M = Mach number _ m = mass flow, kg∕s p = pressure, N∕m 2 T = temperature, K β = shock angle, deg γ = ratio of specific heats θ = deflection angle, deg Π = pressure ratio ρ = density, kg∕m 3 Subscripts cl = cowl closure i = internal portion isentr. = isentropic Kantr. = Kantrowitz m = modified max = maximum poly. = polynomial semiemp. = semiempirical t, tot = total th = throat ∞ = freestream condition Superscript = chocked conditions

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Section: A Literature Reviewmentioning

confidence: 99%

mentioning

confidence: 99%

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Modified Kantrowitz Starting Criteria for Mixed Compression Supersonic Intakes

Flock

Gülhan

2019

AIAA Journal

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“…A so-called strong-shock design principle was proposed by Veillard et al [17], which is to an extent comparable to the rear-side truncation, and with which intake starting could be enhanced. For more detailed information on intake starting, please refer to [18][19][20][21].…”

Section: Rear-side Truncationmentioning

confidence: 99%

Viscous Effects and Truncation Effects in Axisymmetric Busemann Scramjet Intakes

Flock

Gülhan

2016

AIAA Journal

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During Busemann intake design, two constraints have to be considered. First, caused by the displacement of the boundary layer, the pressure levels in a Busemann intake were higher (≈40%) than the values predicted analytically; these effects were labeled viscous effects. Second, truncating the flowfield also changed the properties of the classical Busemann flow; these effects were labeled truncation effects, and it can be distinguished between truncating the intake at the leading edge and at the rear side. To take into account viscous effects, the boundary-layer displacement thickness was calculated with an integral method and added to the inviscid Busemann contour. To quantify leadingedge truncation effects, an oblique shock at the leading edge was assumed, and the pressure at the intake exit was corrected with the continuity equation. The change in flow properties during the rear-side truncation was calculated with a stream-thrust analysis. The effects were separately investigated with Reynolds-averaged Navier-Stokes and Euler simulations, respectively. After the viscous correction, the deviation between numerically and analytically calculated pressure level was below 10%. When truncating the intake, the numerically calculated average pressure and temperature levels were within 1% of the analytical values.

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“…Researchers have carried out a large number of experiments and numerical simulations on the structure optimization, performance evaluation, flow and combustion calculation of the scramjet engine and its inlet. Effective work [1,2,3,4]. The flow field inside and outside the hypersonic inlet is very complicated and is a typical three-dimensional flow.…”

Section: Introductionmentioning

confidence: 99%

Study on Three-Dimensional Inner Flow Field Characteristics and Performance of Scramjet

2019

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The three-dimensional characteristics and performance of the flow field in the inlet of the scramjet engine were numerically simulated by CFD software. The flow characteristics in the width direction of the inlet and the influence of the aspect ratio on the performance of the inlet were studied. The calculation results show that the inlet flow has obvious three-dimensional characteristics, and the flow field structure is different in the width direction from the middle symmetrical section to the side wall surface, the Mach number is smaller and smaller, the static pressure is lower and lower, and the static temperature is higher, the greater the total pressure. The aspect ratio has little effect on the Mach number and static temperature of the outlet section of the inlet, but it has a great influence on the static pressure and total pressure. Within a reasonable range, the aspect ratio is doubled, the static pressure is increased by about 40%, and the total pressure is increased by about 84%. The inlet flow coefficient and the total pressure recovery coefficient increase as the aspect ratio increases. Within a reasonable range, the aspect ratio is doubled, the inlet flow coefficient is increased by approximately 53%, and the total pressure recovery coefficient is increased by approximately 83%.

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Experimental Investigation of the Starting Behavior of a Three-Dimensional Scramjet Intake

Cited by 26 publications

References 16 publications

Modified Kantrowitz Starting Criteria for Mixed Compression Supersonic Intakes

Modified Kantrowitz Starting Criteria for Mixed Compression Supersonic Intakes

Viscous Effects and Truncation Effects in Axisymmetric Busemann Scramjet Intakes

Study on Three-Dimensional Inner Flow Field Characteristics and Performance of Scramjet

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