[American Institute of Aeronautics and Astronautics 40th AIAA/ASME/SAE/ASEE Joint Propulsion...

1 American Institute of Aeronautics and Astronautics

Mixing in Confined Supersonic Flow Past Strut Based Cavity and Ramps

O.J. Shreenivasan∗ , Rakesh Kumar+, T. Sai Kumar‡, R.I. Sujith§ and S. R. Chakravarthy§

Department of Aerospace Engineering,

Indian Institute of Technology Madras, Chennai 600036, India.

An array of carefully chosen configurations based on cavities and ramp mixers were examined for their efficacy in the enhancement of fuel-air mixing in supersonic flows . With the cavities, two back-to-back cavities on the strut, separated by a thin plate, referred to as the “twin cavity” configuration, has been considered along with the case where the thin plate is removed which is the “bottomless” configuration. In both cases, three injection locations are considered, one upstream of the cavity, another downstream of the cavity, and a third at the trailing edge wall of the cavity in the direction opposite to the main flow. The first two configurations have been compared with the cavity less case. In the case of ramps, three different injection locations were chosen, one pertaining to far upstream and another just behind the ramps, whereas a third location is at the base of the strut. The performances of all configurations are compared in the form of mole fraction contours. Static pressure measurements along the length of the test section and the combustor are compared. It is found that the cavity mixers fare better in terms of mixing enhancement and length required for achieving good mixing, when compared to the ramp mixers. Among the three different injection locations with cavities, the order of superior ability for mixing enhancement is the upstream location, followed by the downstream location, and then the opposing injection from the trailing edge wall of the cavity. In the case of ramp mixers, injection just upstream of the ramps is superior to injection far upstream, followed by base injection which shows the poorest mixing of all three injection locations.

I. Introduction

Human quest for high performance and low-cost flying machine which can take them to space has given rise to the study of hypersonic flights. Air-breathing propulsion systems offer the potential of higher performance than rocket engines for hypersonic flight. At supersonic Mach numbers turbojets and ramjet are somewhat comparable. For Mach numbers greater than 3, turbojet and ramjet (Mach 6) engines cannot operate due to material limitation. Therefore, for sustained and efficient atmospheric flight at Mach numbers above 6, a “Scramjet engine” is the only choice.

The Scramjet engine potentially offers outstanding specific impulse performance at hypersonic Mach numbers. The loss of energy in the flow through the engine is less than in a ramjet engine, but supersonic combustion represents a major technological challenge in engine development. The existence of supersonic flow in the combustor presents the problem of how to manage ‘efficient’ and ‘effective’ mixing and burning of fuel for the extremely short residence time the working fluid is in the combustion chamber.

Several techniques have been suggested to enhance the turbulence and mixing of the jets in supersonic flows. It has been realized that the primary task of the mixing enhancement in scramjet combustors is to understand the behavior of the secondary fuel jet injected into the primary oxidizer stream (air). Then, injection techniques could be adopted to enhance the mixing with minimum total pressure losses and combustor lengths.

* Project Officer, Department of Aerospace Engineering, IIT Madras, Chennai, India. Email: [email protected] + Post-Graduate Student, Department of Aerospace Engineering, IIT Madras, Chennai, India. ‡ Undergraduate Student, Department of Aerospace Engineering, IIT Madras, Chennai, India. § Associate Professor, Department of Aerospace Engineering, IIT Madras, Chennai, India. Member AIAA

40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit11 - 14 July 2004, Fort Lauderdale, Florida

AIAA 2004-4194

Copyright © 2004 by O.J. Shreenivasan, Rakesh Kumar, T. Sai Kumar, R.I. Sujith and S. R. Chakravarthy. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.


Of the several ways of injecting a secondary gaseous streams into a supersonic primary flow, transverse jet injection into a supersonic flow10 (TJISF) has been focused upon, in order to obtain fundamental information on the processes associated with secondary injection, and in particular, to determine the similarity rules involved. Early studies on TJISF have been reported Billig et al and Zukoski et al. These works have outlined several different physical and mathematical concepts to predict the behavior of the jet penetration and trajectory. The unified model of gaseous jet penetration developed1 was based on the similarity that exists between the jet injected into a quiescent medium and the jet injected into a supersonic cross flow.

The objective of this paper is to investigate experimentally the mixing of transversely injected choked jets in supersonic cross flow. In order to enhance the mixing of an injected plume into a supersonic free stream, combinations of strut-cavities/ramps are used with variation in injection locations. The test setup details are explained in section II under facility and test setup details, followed measurement technique which gives a brief idea about optical diagnostic setup, image processing and static pressure measurements.

II. Experimental setup

A. Facility and Test setup Details

The air storage system consists of a compressor, reservoir and distribution lines to the setup. An eight-inch pipeline is drawn from the reservoir to the experimental setup with proper distribution line components. These lines have bourdon type pressure gauges for measuring air pressure in the line. For the secondary air injection a separate line is drawn from another compressor. The schematic of the various parts of the experimental setup are shown in Fig.1. The C-D nozzle used is of 40 x 11.85 mm throat area and 40 x 20 mm exit area.

Figure 1.Schematic of the experimental setup and details of the twin nozzle used.

An aerosol generator is used to seed the injected air stream with tiny oil particles. Compressed air with 0.5 to 1.5-bar pressure difference with respect to the outlet pressure is applied to the laskin nozzles, which creates air bubbles within the liquid. Due to shear stress induced by the tiny sonic jets small droplets are generated and carried inside the bubbles towards the oil surface. The impactor plate retains big particles. Small particles escape through the holes and reach the aerosol generator outlet. Vegetable oil is the most commonly used liquid. Most vegetable oils lead to polydisperse distribution with mean diameters of approximately 1 µm12. The injected jet is seeded with these oil particles to illuminate the flow.

The cross-section of the test section is 40 x 20 mm and 120 mm long. The extension length is of 360 mm and has a cross-section of 40 x 60 mm. The dimensions of the struts used are 120 x 40 x 20 mm. Both test section and extension length sidewalls are made of float glass for optical access. The Struts, connecting flanges, top wall and bottom wall are made of ebonite sheet. The dull black color of the ebonite sheet minimizes the reflections of the laser light used which helps to reduce the background noise. The various configurations of Struts used for the study are shown Fig. 2.1 and Fig. 2.2.

Air supply From Reservoir

Air from Compressor

Aerosol generator

Settling Chamber

Twin C-D Nozzle

Test Section

Extension Length

Gate Valve

Bourdon type Pressure gauge

Bourdon type Pressure gauge

Shut-off Valve

Strut


Figure 2.1.Set of strut based cavity configurations

Figure 2.2.Set of strut based ramp configurations B. Measurement Technique 1. Optical Diagnostic setup

Planar Mie scattering imaging is performed to visualize the jet spread and mixing of the injected jet in the main flow. The schematic of the optical setup is shown in Fig. 3. Helium-Neon laser that emits laser light in the visible spectrum (wavelength range 632.8 nm) acts as the illumination source. To get a planar data a thin sheet of light required so, the laser beam is passed through a small pinhole of 1 mm size. The beam is then passed through a combination of cylindrical and spherical lenses to obtain a sheet of 60 mm width. The whole assembly comprising laser, cylindrical and spherical lenses is mounted on an optical bench traverse system, so that the light sheet could be positioned at any required location in the test section.

20

40 60 20 10

40

Φ2

20

20

Top view

Side view CASE C1A

CASE C1B

Side view

40 20

70 50

M=2 20

Side view

CASE C1C

Top view Φ2

20

40 60 20 10

40

Φ2

20

20

Top view

Side view CASE C2A

CASE C2B

Side view

20

30 90

40

Φ2

20

CASE C2C

Top view

Side view

Top view

40

Side view

Side view

20

20

40 60 20

CASE C3A

CASE C3B

40

18.6

120

20

Top view

Top view Dia 2 18.6

120

20 10 10 10

5

5

CASE R1A Ramp

CASE R1B

50

150 5

Side view of both cases

20

18.6

40

40

40

18.6

120

20

Top view

Top view Dia 2 18.6

120

20 10 10 10

5

5

CASE R2A Ramp

CASE R2B

150 5

Side view of R2A & R2B

20

18.6

20

Side view

Top view

40

120

18.6

20

5

18.6

150

CASE R3

All Dimensions are in mm

All Dimensions are in mm


A 16-bit gray scale thermo electrically cooled CCD camera, ST-6 model from Santa Barbara Instruments, is used to capture the image. The camera is 40° to the plane in the test section where the laser sheet passes. To acquire image at some other location, the camera and the laser sheet are moved together as they are mounted on the same traverse system. 2. Image Acquisition and Processing

In the present study, digital image processing methodology is adopted to quantify mixing in terms of the mole fraction distribution of the injected jet. The methodology involves collecting the planar intensity signal of the light scattered from the fine droplets tracing the injected flow. The scattered light intensity is recorded by thermo -electrically cooled CCD camera. The images are acquired in planes perpendicular to the duct axis at various locations downstream of the injection location.

While imaging, a lot of precautions have to be taken to ensure that the quality of the image is amenable for digital processing. The scattered light intensity from the droplets depends on various parameters such as the dependence on local density, temperature (in compressible flows), incident laser intensity, particle size, and number density of the droplets in the plane of measurements. Apart from these, noise in the image greatly affects the outcome of the processing. These parameters vary relatively independently, and hence correction methods can be applied.

There are two specific types of band pass filters, a high-pass filter and a low-pass filter. A high-pass filter allows high frequencies and filters low frequencies (e.g., to enhance sharp edges in the image), whereas a low-pass filter filters high frequencies and allows low frequencies (e.g., to smoothen sharp edge). In the present studies, spatial filtering is done to remove noise and to smoothen the image. Due to variations in the seeding droplet distribution and in intensity due to electrical noise, there always exists high frequency noise (abrupt changes in intensity levels between neighboring pixels). Hence, to remove this, a low-pass median filter (7 x 7) is used. This produces a smooth variation in pixel intensities in regions in the image where a high frequency variation exists.

The flat-field correction is performed to take into account two factors, the variation in the laser intensity across the plane and the variation in local densities due to the non-uniformity of the Mach number across the flow cross section. The images are filtered before they are corrected for flat field. The flat-field correction involves acquiring a ‘flat-field image’ of the flow cross-section with the main flow as well as the injection flow uniformly seeded, at the same location and under identical operating conditions and optical arrangement as when the flow cross-section is imaged with seeding the injectant alone. The latter is referred to here as the ‘injection image’. To achieve uniform seeding, the flow is seeded inside the settling chamber at x/D = 750 upstream of the nozzle. To maintain uniform seeding in both the main flow and the injection, air in the settling chamber is drawn for injection. The variation of in the intensity of the flat-field image thus account for variations in the local density of the flow field and in the intensity of the incident laser sheet. For flat-field correction, the pixel intensities in the injection image are divided by those in the corresponding flat-field image and multiplied by the average of the flat-field image. Multiplying with appropriate correction factor to obtain the mole fraction distribution normalizes these images. The mass flow rate

He-Ne laser

Cylindrical Lens

Spherical lens Pinhole

Center Axis

CCD Camera

40°

Test section

Laser light sheet Laser beam

Figure 3.Schematic of Optical Diagnostic Set-up


was maintained constant at all the injection locations and hence the images can be normalized with the same correction factor. The image acquired at the injection location of normal injection scheme is used for normalizing all the images acquired at various injection locations. The correction factor is obtained by dividing the image at the normal injection location divided by the corresponding image at a given location.

This can also eliminate the non-uniformity in illumination, since both the images will be illuminated in the same fashion, and can be mathematically expressed as follows: I1(x, y), the intensity of the image with the injectant jet alone seeded can be written as

I1(x, y) = Ii(x, y) T(x, y) f1 Ninj(x, y) (1)

Where Ninj(x, y) is the injectant number density, f1 is the seeding fraction, T(x, y) is the thermodynamic dependency function depending on temperature and pressure and Ii(x, y) is the incident intensity. Similarly, the intensity of the flat field image with both the main flow and the injectant jet seeded (both the jets with the same seeding fraction f2) can be written as

I2 (x, y) = Ii(x, y) T(x, y) f2 [Nmain_flow(x, y) + Ninj(x, y)] (2)

I1 (x, y)/ I2(x, y) = C {Ninj(x, y)/ [Nmain_flow(x, y) + Ninj(x, y)]} (3) Where Nmain_flow(x, y) is the main flow number density, C is the Correction factor. The above discussions mandate that the images have to be corrected for the electronic noise (by low pass filter), the spatial variation of laser intensity (by flat field correction), and finally temporal variation of laser intensity (by normalization using constant sum). These processes had to be performed on each image. The Mie scattering intensities are proportional to the number density of the injected species. Thus the number density given by the images can be translated to the injectant mole fraction contours in the flow field.

3. Wall static pressure measurements

Usually the pressure distribution along the flow direction in supersonic flow is controlled by the complex pattern of shocks reflecting from all four walls and thus generating pressure gradients in the flow field. The wall pressure distribution is extracted from the wall pressure taps along the tunnel centerline. The schematic of the pressure tap is shown in Fig. 4.

All dimensions are in mm

Top view

15 EACH

30 45

Test section Extension duct 120 360

Front View

27 Pressure taps at a distance of 15 mm gap

Figure 4.Schematic of pressure tap locations


Pressure measurements are obtained from 27 pressure taps located throughout the test section and extension

duct as shown in the above schematic diagram. These measurements are made using traditional pressure taps (1.5 mm diameter) to sense the mean wall static pressure. The taps are connected to multichannel pressure scanning system. The transducer in this system has quoted measurement uncertainties of less than 0.05% of full scale.

III. Results and Discussion

An experimental investigation was conducted to compare the performance of the strut based cavity and strut

based ramps of different configurations to enhance mixing in supersonic flow. The stagnation pressure was maintained at 8 bars absolute with a mass flow rate of 1.76 Kg/s for the primary flow corresponding to Mach number 2 and the injection pressure at 7.2 bars absolute with a mass flow rate of 0.036 Kg/s. The injection holes were choked for these pressure conditions. For the above conditions the equivalent equivalence ratio was 0.7. The mole fraction contours was obtained as explained above in the image processing section. The scope of the investigation was focused on mixing characteristics and wall static pressure distributions for different cases. A. Mixing Characteristics

This part discusses the result of mixing of secondary jet into a primary flow of Mach number 2.0 past a rectangular cavity and unswept compression ramps of height 5.0 mm. The secondary jet is injected at different positions in the test section, mainly in the vicinity of cavity and ramps. Although the Mie-images were acquired for 16 locations for each configuration, data is presented only for those locations that exhibit physically significant changes, with mention on similar behavior for other cases. Injected mole fraction distributions were recorded directly across the flow field in Y-Z planes in order to directly show the evolution of the mixing in the flow direction. The cross-flow injectant mole fraction images were acquired at 16 locations, the corresponding x/d locations are shown below each contour plots. The locations are normalized with the diameter (d=2.0 mm) of the injection orifice.

Owing to the very large amount of mie scattering images, only profiles at selected locations were chosen to be included in the data presented here for comparison. Also the locations and its corresponding images selected for comparison is based on the criteria that they should exhibit the most significant difference. These figures offer a qualitative scenario of mixing in terms of span-wise spreading and lateral penetration. Only six of these sixteen injectant mole-fraction images are shown in Fig 5.1-5.3 used for comparison purposes and similar trend is followed for the ramp cases shown in Fig 6.1-6.3 as well.

From Fig 5.1, mole fraction distribution for the downstream transverse injection case of strut based cavity configuration, it can be observed that bottomless cavity mixers are better than twin cavity mixers. These results are better when compared with no cavity case (case C1C).

Figure 5.2 gives the mole fraction contours for the upstream injection in strut-based Cavity. This injection location yields better mixing than the previous case (downstream injection). However, the twin cavity mixers are better than bottom less cavity mixers for upstream injection. Again, both cavity mixers are better than cavity less case.

Figure 5.3 shows the mole fraction contours for opposed injection in to the cavity. This configuration appears inferior to the previous two. It is also observed that mixing is better for bottomless configuration than for twin cavity.

From the mole fraction contours shown in Fig 6.1, it is realized that case R1A is superior to R1B. Hence for the transverse injection far upstream cases from the ramp edge, the line of injection is important for the efficacy point of view. The injection line falling between the crest of ramps shows promis ing results as evident from the injectant mole fraction contours. In both cases the streamwise vortex of the ramp begins to transport the injectant away from the jet.

Co mparative analysis of angular injection just at the base of ramp for R2A and R2B is shown in Fig 6.2. Comparing the injected mole fraction contour at these locations for both the cases it is seen that angular injection


parallel to ramp surface just at its base is superior to the angular injection in between the crest of the ramps at its base.

In the case of the oblique injection from the base of the strut (R3), the injectant mole fraction contours as shown in Fig. 6.3, it can be observed that the mixing is poor in this case compared to the upstream and angular injection. Overall, this particular case of strut based ramp shows the poorest performance among all cases.

62.5

75.0 90.0

155.0

x/d=0.0

110.0

62.5

75.0 90.0

155.0

x/d=0.0

110.0

62.5

75.0 90.0

155.0

x/d=0.0

110.0

Figure 5.1.Mole fraction distribution in cross-sectional planes for downstream

transverse injection of cavity case (C1).

C1A

C1C

C1B


62.5

77.5

102.5

175.0

x/d=0.0

120.0

62.5

77.5

102.5

175.0

x/d=0.0

120.0

62.5

77.5

102.5

175.0

x/d=0.0

120.0

Figure 5.2.Mole fraction distribution in cross-sectional planes for upstream transverse

injection of cavity (C2).

C2A

C2C

C2B


Figure 5.3.Mole fraction distribution in cross-sectional planes for parallel injection inside the

cavity (C3).

47.5

62.5

80.0

130.0

x/d=0.0

105.0

47.5

62.5

80.0

130.0

x/d=0.0

105.0

C3A

C3B


Figure 6.1.Mole fraction distribution in cross-sectional planes for transverse injection far

upstream of ramp bases (R1).

46.8

61.8

84.3

149.3

x/d=0.0

99.3

46.8

61.8

84.3

149.3

x/d=0.0

99.3


Figure 6.2.Mole fraction distribution in cross-sectional planes for angular injection just at the

base of ramp (R2).

53.6

83.6

103.6

248.6

x/d=0.0

188.6

53.6

83.6

103.6

248.6

x/d=0.0

188.6


B. Wall Static Pressure Profiles

Figures 7.1-7.6 shows the distribution of normalized wall static pressure Pabs/Patm for all strut bases cases of cavities and ramps. The wall static pressures are normalized by the free stream static pressure, and results are plotted as a function of effective distance normalized with diameter of the injection orifice‘d’.

The increase in static pressure near the cavity region in the absence and presence of injection clearly explains the expected phenomena. As expected, a compression wave forms at the separation corner resulting in increased pressure (relative to free stream static pressure) in the cavity. The shear layer experiences recompression at the aft wall, leading to higher pressure on the near wall. There is further rise in this static pressure near cavity when there is injection in the vicinity of cavity which is clearly observed in the pressure plots (Fig 7.1-7.3). Almost for all cases static pressure near the point of injection has increased as compared to cases in the absence of injection.

Static pressure also rises near the expansion region of the test section exit. Furthermore, rise and fall of static pressures are evident due to complex mechanism of reflecting shock waves from the wall surfaces and due to the complex flow field generated downstream of strut.

In the extension duct the injection has less effect on local wall static pressures. Influential region for wall static pressure is just at the point of injection and approximately 80 mm downstream of it for all cavity cases with transverse injection. But in the case of opposed injection inside the cavity, rise in static pressure is comparatively less. In the case of bottomless cavity with opposed injection this distance over which there is change in static pressure is approximately 15-20 mm down stream of injection location.

For strut based ramp configurations again a similar trend was found. Static pressure increased sharply at the point of injection due to transverse injection far upstream and angular injection just at the ramp base cases. However there was no significant change in wall static pressure due the angular injection from the base of the strut (R3) case of strut-based ramp configuration. It more or less followed the same rises and falls in static pressure in the complex flow field for both in the presence and absence of injection.

17.5

42.5 65

130

x/d=5

85

Figure 6.3.Mole fraction distribution in cross-sectional planes for downstream

transverse injection of cavity case (C1).


Wall Static Pressure plot for C1

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

-50 0 50 100 150 200 250

X/D

P(a

bs)

/ P(a

tm)

C1A without injection C1A with injection

C1B without injection C1B with injection

C1C without injection C1C with injection

Figure 7.1 Wall Static Pressure profiles for transverse injection downstream of cavity

Figure 7.2 Wall Static Pressure profiles for transverse injection upstream of cavity

Wall Static Pressure for C2

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

0 50 100 150 200 250

X/D

P(a

bs)

/ P

(atm

)



C2C without injection C2C with injection


Wall Static Pressure plot for R1

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

-50 0 50 100 150 200 250

X/D

P(a

bs)

/ P(a

tm)

R1A without injection R1A with injection

R1B without injection R1B with injection

Figure 7.3 Wall static pressure profile for opposed injection inside the cavity

Figure 7.4 Wall static pressure profile for transverse injection far upstream of ramps

Wall Static Pressure plot for C3

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

-50 0 50 100 150 200 250

X/D

P(a

bs)

/ P

(atm

)




Figure 7.5 Wall static pressure profile for angular injection just at the base of ramp.

Figure 7.6 Wall static pressure profile for angular injection from the strut base with ramp .


0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

-50 0 50 100 150 200

X/D

P(a

bs)

/ P

(atm

)

R2A without injection R2A with injectionR2B without injection R2B with injection


0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

-100 -50 0 50 100 150 200

X/D

P(a

bs)

/ P

(atm

)

R3 without injection R3 with injection


IV. Summary

An array of carefully chosen configurations based on cavities and ramp mixers are examined for their efficacy in the enhancement of fuel-air mixing in supersonic flows. The cavities and the ramp mixers are mounted on struts in a typical dual-mode ramjet configuration. With the cavities, two back-to-back cavities on the strut, separated by a thin plate, referred to as the “twin cavity” configuration, has been considered along with the case where the thin plate is removed, which is referred to as the bottomless cavity. In both cases, three injection locations are considered, one upstream of the cavity, another downstream of the cavity, and the third at the trailing edge wall of the cavity in the direction opposite to the main flow. The first two configurations have been compared with the cavity less case. In the cases with ramps, two injection locations pertain to somewhat far upstream and just behind the ramps, whereas a third location is at the base of the strut. In the last two cases, the injection angle is oblique, and along the ramp angle. In the first two cases, two further sub-cases are injection aligned or out-of-line with the ramps. In general, it is found that the cavity mixers fare better in terms of mixing enhancement and length required for achieving good mixing, when compared to the ramp mixers. Among the three different injection locations with cavities, the order of superior ability for mixing enhancement is the upstream location, followed by the downstream location, and then the opposing injection from the trailing edge wall of the cavity. The last result is counter-intuitive, since opposing injection might be expected to obtain better mixing within the cavity, but the penetration of the injectant emerging out of the cavity into the main flow is poor, no matter how well mixed within the cavity. With upstream injection, the twin cavity is slightly superior to the bottomless cavity, whereas with downstream injection, the opposite is the case. Both of these injection strategies register a significant improvement relative to the cavity less case. With ramp mixers, injection just upstream of the ramps is superior to injection far upstream, although more residence time is afforded in the latter case. Similarly, base injection shows the poorest mixing of all the three injection location. These results affirm the view that injection just at the location of generation of the axial vortices enabled by the ramps is the best practice. Further, it is also considered better to inject out-of-line with the ramps than in line with the ramps, since the latter leads to a good large-scale mixing but poor small-scale mixing which is required from the point of view of good combustion efficiency in a dual mode ramjet combustor. Acknowledgement This work was funded by the Vikram Sarabhai Space Centre (VSSC). The authors wish to thank JDA, Rajesh Ramakrishnan of Indian Space Research Organization (VSSC, ISRO) for there support. References 1. Billig, F. S., Orth, R. C., and Lasky, M., (1971) A unified analysis of gaseous jet penetration. AIAA Journal,

9(6), June, 1048-1058. 2. Clemens, N. T., Mungal, M. G. (1991) A planar Mie scattering technique for visualizing supersonic mixing

flows. Experiments in Fluids, 11, pp. 175-185. 3. Daniel, J. C., and Graves, J. (1988) Laser-Induced-Fluorescence Visualisation of transverse gaseous injection in

a non-reacting supersonic combustor, 4(6), November-December, 591-97 4. Goro Masuya, Tomoyuki Komuro, Atsuo Murakami, Motohide Murayama and Katsura Ohwaki. (1995)

Ignition and Combustion performance of scramjet combustors with fuel injection struts, Journal of Propulsion and Power. vol 11, No. 2

5. Gullet, B. K., Groff, P. W., and Stefanski, L. A. (1993) Mixing quantification by visual imaging analysis, Experiments in Fluids, 15, 443-451.

6. Heller, H. H. (1971) Flow- induced pressure oscillations in shallow cavities. Journal of Sound and Vibrations. 18(4), 545-553.

7. Liscinsky, D. S., True, B., and Holdeman, J. D. (1994) Mixing characteristics of directly opposed rows of jets injected normal to a cross flow in a rectangular duct, AIAA Paper-94-0217.


8. Muruganandam, T. M., Srihari Lakshmi, A. A. Ramesh, S. R. Viswamurthy, R. I. Sujith, and B. M. Sivaram et al. (1999) Mixing of transversely injected jets into a crossflow under low-density conditions. AIAA Journal, 40(7), July, 1-7.

9. Schetz, J, A., and Billig, S. F., (1966) Penetration of gaseous jets injected into a supersonic stream. Journal of Spacecraft , 3(11), November, 1658-1665

10. VanLerberghe, Wayne, M., Santiago, J. G., Dutton, J. C., Lucht, R, P., (2000) Mixing of a sonic transverse jet injected into a supersonic flow. AIAA Journal, 38(3), March, 470-479

11. Zukoski, E. E and Spaid, F. W. (1964) Secondary injection of gases into a supersonic flow. AIAA Journal, 2(10), October 1689-1696.

12. Raffel, M., C.E. Willert, and J. Lompenhans (1998) Particle Image Velocimetry, A practical guide. Ny: Springer.

[American Institute of Aeronautics and Astronautics 40th AIAA/ASME/SAE/ASEE Joint Propulsion...

Documents

Transcript of [American Institute of Aeronautics and Astronautics 40th AIAA/ASME/SAE/ASEE Joint Propulsion...