A numerical investigation of supersonic inlet using implicit TVD scheme

Shigematsu, Junji; Yamamoto, Kazuomi; Shiraishi, Kazuo; Tanaka, Atsushige

doi:10.2514/6.1990-2135

Cited by 9 publications

(2 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In fact, one would like to drop this term to gain extra stability to converge to the final solution. The matrix is subtracted from a to account for the shock-capturing term as shown in Equation (9). The application of this formulation to compute various internal and external flows can be found in our earlier articles [24,25,30,32].…”

Section: Finite-element Formulationmentioning

confidence: 99%

Viscous flow in a mixed compression intake

Kotteda

Mittal

2010

Numerical Methods in Fluids

View full text Add to dashboard Cite

Numerical simulation of the flow in a two-dimensional mixed compression intake is carried out by solving unsteady viscous compressible equations using a stabilized finite element method. The effect of bleed in starting/unstarting of the intake and controlling the buzz instability is investigated in detail. Higher bleed leads to an increase in the ability of the intake to sustain larger back-pressure for stable operation. The amount of bleed and its location is varied to understand its effect on the performance of the intake. Two kinds of unsteady oscillations are observed: 'little' and 'big' buzz. The frequency of the both kinds of buzz oscillations is found to be super-harmonic of the fundamental acoustic frequency of intake modeled as an open-closed organ pipe. The frequency as well as amplitudes of the big buzz cycles is larger than those of the little buzz. The little-and big-buzz are found to occur for low-and high-subcritical state of the intake and are very similar to Ferri and Dailey criteria, respectively. Buzz is eliminated when relatively high bleed is implemented, both, upstream and downstream of the throat. The effect of rate of change of back-pressure on the start/unstart of the intake is investigated. Two situations are considered. The first case is that of an intake where the back-pressure remains below the critical value. It is found that the intake remains started if the change in back-pressure is gradual. However, it unstarts if the back-pressure is changed relatively rapidly. The second set of simulations is an attempt to model the situation where the back-pressure at the exit of the intake exceeds the critical value and a logic is incorporated in the feed back loop of the fuel modulation to start the intake. Low rate of change of pressure is unsuccessful in starting the intake. Relatively high rates result in either a quick starting of the intake or a slow unstart. and forth in the convergent portion leading to high unsteadiness in the flow. It involves periodic filling and discharge of the plenum chamber, complex shock-boundary layer interaction, shear layer/slip stream-boundary layer interaction, transient shock movement and flow separation. It adversely affects the mass flow entering the engine and may lead to combustion instability, engine surge and flame out. It can also lead to deterioration of the performance of propulsion system, thus causing catastrophic loss in thrust.The buzz instability was first reported by Oswatitsch [3]. The tests were conducted for supersonic missile flights for Mach number in the range of 2.5-3.0. He observed buzz during his experiments, but disregarded it on the basis that a sub-critical range of operation is impractical and, therefore, not important. Later (1945)(1946)(1947)(1948)(1949)(1950)(1951)(1952)(1953)(1954)(1955), buzz was observed in many of the extensive experiments that were conducted at NASA, Langley on external compression inlets. Ferri and Nucci [4] conducted detailed experiments on an axisymmetrical external compression air intake. The occur...

show abstract

Section: Finite-element Formulationmentioning

confidence: 99%

Viscous flow in a mixed compression intake

Kotteda

Mittal

2010

Numerical Methods in Fluids

View full text Add to dashboard Cite

show abstract

“…Although, many computational studies [2][3][4][5][6][7][8] pertaining to various issues of isolated air intake including the unsteady flow [4,5], buzz phenomena [6,7] appeared in the literature, numerical studies for installed air intake are very few. The performance of individual intakes gets modified due to changed entry flow conditions when it is installed to the core body at a downstream location.…”

Section: Introductionmentioning

confidence: 99%

CFD Prediction of Ramjet Intake Characteristics at Angle of Attack

Saha,

Sinha,

Chakraborty

2023

joast

View full text Add to dashboard Cite

The characteristics of installed intakes of a ramjet engine at angle of attack are predicted numerically. Three dimensional Navier Stokes equations are solved alongwith k - ε turbulence model using commercial CFD software. The software was first validated for isolated intake and computed results match very well with theoretical results available in literature. Pressure recovery Vs. mass flow characteristics of four installed intakes placed in a rear location of a ramjet vehicle is evaluated at different angles of attack upto 6°. Intake performance matches reasonably well with experimental results. It has been observed that significant variation of intake performance exists between windward and leeward intakes. For higher angle of attack, the leeward intake move towards the subcritical operation faster and the intake flowfield is seen to interact with the corebody boundary layer causing significant spillage.

show abstract

Characteristics of the inlet with the pressure perturbation in the ramjet engine

Shin

Kang

2006

J Mech Sci Technol

View full text Add to dashboard Cite

A numerical investigation of supersonic inlet using implicit TVD scheme

Cited by 9 publications

References 3 publications

Viscous flow in a mixed compression intake

Viscous flow in a mixed compression intake

CFD Prediction of Ramjet Intake Characteristics at Angle of Attack

Characteristics of the inlet with the pressure perturbation in the ramjet engine

Contact Info

Product

Resources

About