Comparison of Computational Analysis of A Hypersonic Aero-Disk Model with Slots and Greater Aero-Disk Size

Comparison of Computational Analysis of A Hypersonic Aero-Disk Model with Slots and Greater Aero-Disk Size

G. Sai Pradyoth

Aeronautical Engineering

Institute of Aeronautical Engineering College Hyderabad, India

G. Rakesh

Aeronautical Engineering

Institute of Aeronautical Engineering College Hyderabad, India

B. Vinod Kumar

Aeronautical Engineering

Institute of Aeronautical Engineering College Hyderabad, India

Abstract: The most basic issues looked by the architects in the field of hyper-Sonics is the streamlined warming on the out- side of hypersonic vehicles. At high Mach number, hypersonic vehicles, for example, re-entry cases, rockets, rockets experi- ence gigantic measure of warming at the nose partition which may prompt the harm of the inner segments. Some of the time the warming is enormous to the point that the entire design of the vehicle may get totally crumbled. Many methods such as aero-spike, aero-disk, reverse flow injection, ablation tiles, heat resistant coating, titanium-alloyed materials, fiber rein- forced carbon composites (FRCCs), etc. are invented by re- nowned scientists across the globe which are used even today. In this research, basic aero-disk models are first designed in CATIA with two different aero disk models. Then CFD anal- ysis is carried out using ANSYS-CFX to study, examine and compare the heat reduction in the models. The research com- pares between the model slotted arm and a design with differ- ent disk diameter and shows which has more efficiency in reducing the stagnation heat flux and load acting on the nose cone compared to the other aero-disk model thereby, allowing it to achieve higher Mach numbers.

Key words: Hyper Sonics, Aerodynamic heating, Aero-disk, Aero-spike, Re-entry

1. INTRODUCTION

   Hypersonic aerodynamics has been one of the most chal- lenging fields for engineers in aerospace domain. With advancements in various technologies, engineers are now able to develop hypersonic vehicles such as rockets, mis- siles, re-entry space capsules, etc. which can achieve Mach number more than 5. But the development of a hy- personic vehicle is not easy due to the problem that in a hypersonic flow, the air becomes ionized i.e., the proper- ties of the fluid changes rapidly. Because of the high speed of the hypersonic vehicle, strong shock waves are formed in front of the nose of the vehicle which lead to the increase in the stagnation heat flux thus leads to the rapid heating of the nose of the hypersonic vehicle. This aerodynamic heating has been a challenging issue since many decades. Scientists from all over the world have pro-

   posed, designed, experimented many thermal protection techniques to reduce this aerodynamic heating. Some of which are blunt nosed body concept, use of ablative mate- rials, aero- spikes, aero-disks, etc.

   From the literature survey, it has been found that blunt nose shape is preferred for hypersonic vehicles for the fact that blunt nosed hypersonic vehicles have much lesser aerodynamic heating compared to hypersonic vehicles with conical shaped nose and also it can accommodate more components. This is on the grounds that an blunt nose disconnects the shockwave from the body of the rocket while, on account of the conical nosed rocket, the shockwave is connected to the body prompting expansion in the warming of the outside of the body. The principal case with respect to streamlined warming was capable route back in the German 'V-2 rocket' program where the rockets going at hypersonic speeds launched in the mid- air because of streamlined warming of the rockets.

   FUNDAMENTALS OF HYPER-SONICS:

   Any model put in hypersonic stream i.e., stream having Mach number more than 5, encounters profoundly critical changes in its streamlined qualities like the development of normal & oblique shock waves at the front part of the object which is confronting the free stream, expansion in the temperature behind the shock waves and on the front surface of the model, and furthermore there are changes in other stream medium parameters like density, static and total pressure factors and static and absolute temperatures.

   The hypersonic flight system incorporates climatic passage and reemergence, ground testing, what's more, trip for both fueled and unpowered vehicles. In the current Lec- ture Series, the primary interest is on maintained and con- trolled hypersonic flight, regardless of whether for military or common vehicle application. Despite the fact that it isn't right now ensured for flight, there is one operational hypersonic vehicle: the space transport of NASA. In any event 20 years prior the improvement of the van a huge movement in hyper-

   sonic flight research was led by the US Air Force in their X- 15 program. This vehicle has arrived at a flight Mach number of 6.7 on its last flight, which likewise used to test a hyper- sonic ramjet motor. Direct stun impingement on the arch holding a fake motor caused serious warming also, underly- ing harm, and this was one of numerous exercises gained from the program. Attributable to the plan of the X-15, it was not able to do long-length fueled flight, yet it gave a lot of data on specialized issues that actually stay a genuine.

   For a model with a huge front facing region, typical shocks are normally framed i.e., shock waves opposite to the vehicle of stream heading (point of 90 degrees). For a sharp front facing model or tapered molded model, oblique shock waves are formed i.e., shock waves at a point other than 90 degrees. For a blunt nose model, a shock wave with the blend of both normal and oblique shock waves called bow stun is formed. Shock waves formed on a body can be visualized using techniques like schleren technique, PIV, shadow graph, shock tunnels, hypersonic wind tunnels, Laser dopler technique, etc. It is found that shock waves formed around a blunt body are detached at the leading edge of the blunt body due to its blunt shape. This leads to reduction in the heating at the leading edge of the blunt body. That is why blunt nose is preferred for any hypersonic vehicle body.

   Effect of Aero-Disk on the Model: The aero-disk attached with an arm to the blunt body model has a great effect on the parameters of the flow medium. The aero-disk converts an oblique shock wave into a bow shock due to the blunt shape of the disk. Due to which a re-circulation zone is created behind the disk up to the root of the arm. Recirculation is a particular condition where the stream isolates from the body of the obstruction. This makes a low-pressure region quickly downstream which draws liquid back into this area from the fundamental stream with the net consequence of making a flowing vortex or pair of vortices. This condition makes a stamped expansion in drag contrasted with circumstances where the stream stays connected to the surface. On the off chance that stream partition is likely it is frequently better to purposely induce turbulence early rather than have an abrupt separation of laminar flow. This re-circulation region creates a low-pressure region reducing the temperature in that region and thus, induces cooling effect on the surface of the body. This low-pressure region changes with the change in the arm length and aero-disk diameter. In this analysis, the disk diameter is changed and the arm length is kept constant and added slots to the arm in one model. Research states that aero-disk attachment if used in an optimum manner can become a revolutionary change in the field of aerospace.

2. LITERATURE SURVEY

   • Rahul S. Pawar et al (2019),

   Performed numerical simulation over a blunt body to ana- lyze the effect of drag, lift, and pitching moment coefficient onto the blunt body with and without implementation of an aero spike at Mach number 6. They designed a blunt body model with and without aero-spike attachment and carried

   out the performance analysis of conical aero spike for vari- ous L/D (spike length to diameter) ratios using CFD Expert- Lite solver (developed by M/s Zeus Numerix Pvt. Ltd.).

   Through this examination they discovered that the primary benefit of utilizing air spike is that it substitutes greater force bow stun with lesser power conical shock subsequently makes a re-circulating low pressing factor area beginning from the tip of the nose to the arm end of the aero spike. This re-circulating zone decreases both drag and the stagna- tion heat motion before the unpolished nose of the body.

   Their primary objective was:

   1. To visualize the shock wave structure around the blunt nose with aero-spike.

   2. To study the influence of different L/D ratios as well as angles of attack for drag reduction.

   Figure 1: Blunt body geometry with attached aero spike

   Due to the presence of complexities in the geometry, they chose unstructured mesh. But they also used prism lay- ered mesh near the boundary wall to get the behavior of the fluid near the wall. Since two kinds of mesh were used the mesh type generated was hybrid mesh. The boundary conditions for the flow field are:

   • inlet face – velocity inlet

   • cylindrical face and outlet face pressure far field

   • for body along with spike no slip wall boundary condition

     Surface flow contours for Pressure and Mach number over blunt body and conical aero spike were obtained for the L/D ratios of 1, 1.5, and 2, at zero angle of incidence and Mach 6, as illustrated in figures below.

     It was observed that the implementation of aero spike has a smaller coefficient of drag as compared to the blunt body. This was caused due to the existence of recircula- tion region in between the origin of aero spike up to the point of reattachment at the shoulder of the nose body. As the angle of attack increases, the flow over the aero spike becomes uneven and hence changes the intensity of recir- culation region.

     • Wei Huang et al (2019)

   Wrote a research paper which stated that the mechani- cal spike is an effective way to reduce the aerodynamic drag due to the reduced dynamic pressure in the separated flow region, and when added a disk on the spike nose can yield better performance for thermal protection compared

   with the pointed spike. Further, the flow field around a spiked blunt body appears to be very complex and con- tains a number of interesting flow phenomena and charac- teristics, which are yet to be investigated. Thus, in this paper, the drag and heat flux reduction mechanism in- duced by the aero- disk has been investigated numerically. The spike produces a region of recirculation region which is formed around the root of the spike up to the reattach- ment point of the flow at the shoulder of the blunt body and shields the blunt-nosed body from the incoming hypersonic flow. The size of the recirculating region increases with the increase of the diameter of the aero-disk, especially with the increase of the length of the spike.

   The length of the spike and diameter of the aero-disk both have a great influence on the shape of the recirculation region, and they have to be suitably chosen to obtain a large conical recirculation area in front of the blunt body to obtain maximum heat reduction.

   • Gerdroodbary et al (2010),

     Numerically investigated the effectiveness of aero disk and aero spike attachments as retractable drag and heat reduction devices for large angle blunt cones at dif- ferent angles of attack in hypersonic flow. They obtained full three- dimensional solutions of the compressible Na- vier Stokes equations with k-w turbulence model at a free stream flow Mach number of 5.7 and 3, 7, 10 and 12 de- grees of angles of attack. The heat transfer studies re- vealed that that hemispherical aero disk exhibits the best heat reduction characteristics. They have recommended the use of aero dome with hemispherical aero disk with an L/ D ratio of 1 for optimum drag and heat reduction.

   • Wang et. al (2010),

     The flow fields around a blunt cone with and without aero disk flying at hypersonic Mach numbers are comput- ed numerically by specifying the free stream velocity, static pressure and static temperatures at the inlet of the computational domain with a three-dimensional, steady, Reynolds-averaged NavierStokes equation, and an aero disk is attached to the tip of the rod to reduce the drag and heat flux further. The influences of the length of rod and the diameter of aero disk on the drag and heat flux reduc- tion mechanism are analyzed comprehensively, and eight configurations are considered in the current study.

     Numerically investigated the influences of various nose configurations such as conical, hemispherical & flat headed spike and the L/D ratio of the spike on the aerody- namic drag and heating of blunt bodies. They observed that temperature and pressure contour plots for both hemi- spherical and flatheaded spike to be similar and their aer- odynamics drag reduction capabilities were lesser in those of conical spikes.

   • Ahmed and Qin et al (2010),

   Explored 4 proxy models for the plan enhancement of spiked blunt bodies in hypersonic trip with two plan tar-

   gets of drag and aerodynamic heating assessed inde- pendently. They found that optimizing the spike configu- ration could deliver 92% and 13% decrease in drag and aerodynamic heating individually, contrasted with the unspiked obtuse body. Both advanced plans were found to support exceptionally huge spike lengths request of multi- ple times the diameter of blunt nose, in this manner it very well may be reasoned that the two plan boundaries are not unequivocally rivaling one another.

   OBJECTIVE OF THE RESEARCH:

   In this research, basic aero-disk models are first designed in CATIA with one being slotted and other non-slotted and different aero disk with respect to slotted one. Then CFD analysis is carried out using ANSYS-CFX to study, exam- ine and compare the heat reduction in the models. The research shows that the model with larger disk radius has higher efficiency in reducing the stagnation heat flux on the nose cone compared to the other aero-disk models thereby, allowing it to achieve higher Mach numbers.

3. METHODOLOGY CATIA MODEL DESIGN:

   CATIA (Computer-Aided Three-Dimensional Inter-

   active Application) is a multi-platform software suite for computer-aided design (CAD), computer-aided manufac- turing (CAM), computer-aided engineering (CAE), PLM and 3D, developed by the French based company Dassault Systems. CATIA has numerous in-constructed instruments and highlights that permit us to configuration any sort of mechanical, aviation design based models effectively sav- ing time, energy and cash. In aviation design, CATIA is utilized to plan different segments identified with airplane and shuttle.

   In our project, we used CATIA V5 software to design a total of three models:

   • One basic blunt body model with diameter =

     100mm, blunt nose radius = 50mm, total length = 175mm

   • One blunt body models (same as basic blunt body model) but with an aero-disk of radius

     = 20mm, attached to arm of lengths 150mm respectively.

   • One basic blunt body model with the dimen- sions as mentioned above with aero-disk of

   10mm diameter attached of a definite arm length of 150mm, But slots have been made at specific locations i.e., through the center of the arm axially with diameter of 2mm along with holes on the outer surface of the model with diameter = 2mm.

   • These CATIA files with catpart extension is then convertedto igs extension files be-

   cause ANSYS software can read /write /edit files only with these extensions.

   1. BASIC BLUNT BODY MODEL:

   2. MODELS WITH BIGGER AERO-DISK:

      Figure 4: Aero-disk model with disk radius of 20mm

      Figure 3: Aero-disk model of L/D = 1.5 with slotted-passage

      ANSYS WORKBENCH:

      ANSYS (acronym for Analysis Systems Inc.) is a global public company based in Canonsburg, Pennsylvania which develops and markets multi-physics engineering simulation software for product design, testing and operation. John Swanson founded Ansys in 1970. Ansys acquired other engineering design companies, acquiring additional tech- nology for, electronics design, fluid dynamics and other physics analysis.

      • ANSYS CFX:

        Ansys – CFX is a high-performance computational fluid dynamics (CFD) software tool which delivers accu- rate and reliable solutions robustly and quickly across a wide range of CFD and multi-physics applications. CFX is recognized for its outstanding speed, robustness and accu- racy when simulating turbo machinery, such as fans, com- pressors, pumps and gas & hydraulic turbines.

        Ansys CFX software is a high-performance, gen- eral-purpose fluid dynamics program that engineers have applied to solve wide-ranging fluid flow problems since many years. At the heart of CFX is its advanced solver technology, the key to achieving reliable and accurate solu- tions quickly and robustly. The modern, highly parallelized solver is the foundation for an abundant choice of physical models that capture virtually any type of phenomena relat- ed to fluid flow. The solver and models are wrapped in a modern, intuitive, and flexible GUI and user environment, with extensive capabilities for customization and automa- tion using session files, scripting and a powerful expression language.

        The ANSYS software uses the momentum, conti- nuity and energy equations which are related to pressure, velocity, temperature, volume and density. In some cases, Ansys is also based upon Mach number, Reynolds number etc. The equations that are used in the Naiver-strokes rela- tion were based on integral or differential form and are derived from Euler's equations.

        The Fluid flow – CFX in the ANSYS – workbench consists of the following features:

      • Geometry

      • Mesh

      • Set-up

      • Solution

      • Results

   Figure 5: Slots like passages on the model

   .

   CFD ANALYSIS PROCEDURE: (same for all the fiv models)

   1. First, CATIA model (.stp file) is imported into the Ge- ometry section in the ANSYS- CFX workspace. Then a bounding box with dimensions (250mm * 700mm * 250mm) which represents the fluid domain is created using the Enclosure option in tool bar. Now using the Boolean option, the model is subtracted from the

      bounding box. The INLET, OUTLET, WALL for the models is defined using the named selection option.

      Figure 6: Design Modeler

   2. Second, in the Mesh section, unstructured mesh type is used to create mesh for all the models. The table below describes the statistics of the mesh.

      Figure 7: Meshing for a model Table 1: Mesh statistics for all the three models

      S. No	Models	No of nodes	No of elements
      1	Basic blunt body	408764	2150153
      2	Slotted aero-disk model	220551	1200454
      3	Aero-disk with 20mm dia.	31292	158131

   3. Third, all the boundary conditions are then given in the Set-up section. The boundary conditions used in the analysis are:

      1. Domain Fluid Air = Air ideal gas o Reference pressure = 0 Pa

         • Heat transfer model = Total energy

         • Turbulence model = Shear tress transport

      2. Default domain default No slip wall

      3. Inlet: Flow regime Supersonic

         • Mass & momentum Normal speed (2058 m/s)

         • Heat transfer Static Temperature (288.15 K)

         • Wall: Boundary type Wall

         • Mass & momentum Free slip wall

         • Outlet: Flow regime Supersonic

         • Solver input min. number of iterations = 1

      max. number of iterations = 500

      Figure 8: Pre-processor Setup

   4. Fourth are the Solutions. Double precision option is used here before clicking on the start run option. The iterations keep running until the solution gets completed or converged.

   5. Fifth and the last are the Results. A plane (which cuts the model symmetrically) is created in order to vis- ualize the flow around the model and to obtain vec- tor & streamline plots and all contours related to flow parameters such as density, Mach number, pressure, temperature, total pressure, total tempera- ture and velocity.

   6. Since our research requires temperature values around the boundary of the models, the temperature vs. distance along the models length & the total tem- perature vs. distance along the models length is found using Polyline & Chart option. The poly line option when applied creates a line around the mod- el.

      The following are the settings that are applied to obtain the charts or plots:

      • Location Polyline

      • X axis Y distance

      • Y axis temperature or total temperature

      • Series series 1 APPLY

   Thus, the temperature plots or charts are created. Now these charts can be saved as .csv files using the Ex- port option. The coordinates files can also be saved in a table format using the table option, then after saving the contours, a report consisting of all the information re- garding the CFX analysis is generated using Report pre- view option & can be saved using Publish option.

   .

4. RESULTS & DISCUSSION

   o Flow Visualization Of All The Models:

   The streamline contours obtained from the CFD analy- sis allow us to visualize the flow around all the three mod- els. After the Geometry, mesh, set-up, solution the results are obtained on the plane created and selected by altering the parameters. It is observed from the contours that, the blue colored zones indicate the re-circulation regions formed at the leading edge of the body. These re- circulation zones are low-pressure regions where tempera- tures are low compared to the other regions enclosing the whole model. Thus, the nose portion of the body is protect- ed from the extreme heating due to the strong shock waves formed due to the high-speed passage of air (Mach 6) over the surface of the body.

   Due its blunt nose, a detached bow shock formed at the nose of the blunt body. The re- circulation region formed is not very significantly noticeable. This can be noticed from the contour below.

   Figure 9: Flow visualization over blunt body model

   For the aero-disk model with L/D ratio of 1, a very small re-circulation region is formed at the nose portion which is larger compared to the blunt body model.

   For the slotted aero-disk model, due to slot like pas- sages, there the area of re- circulation region becomes much larger compared to all the above models. These slots send additional amount of low pressured air into the re- circulation zone increasing the low-pressure region in front of the nose part of the model.

   Figure 10: Flow visualization over slotted passage aero-disk model with L/D ratio of 1.5

   For the model with bigger aero-disk i.e. about 20mm radius the re-circulation, due to increase in the disk size there the area of re- circulation region becomes smaller compared to slotted model but the flow has split into two reducing the overall pressure compared to all the above models.

   Figure 11: Flow visualization ver slotted passage aero-disk model with Disk radius 20mm

   By visualizing the flow around all the above models, it can be concluded that aero-disk model which has larger disk diameter has larger re-circulation region compared to the other models in the nose portion starting from behind the aero-disk to the root of the arm. The maximum velocity acting has reduced from 1.980e+03 to 1.29e+03

   o Density Of The Flow Over All The Models:

   From the density contours, we can observe that the region where the shock waves are formed has high density com- pared to all the regions. This is due to accumulation of the air molecules which undergo compression to form the shock waves. Due to the blunt shape of the nose of the blunt body model, a strong bow shock of formed in front of the nose resulting in the aero-dynamic heating at the nose part.

   Figure 12: Density contour for the blunt body model

   Due to presence of slot like passages in the below model, the air through the passages increase the distance between

   Figure 14: Density contour for the aero-disk model with disk radius of 20mm

   Even after increasing the disk diameter the main blunt head has some effect of density around it. In this case the design with slotted arm deals with density better the altered blunt head design.

   the high density zone away from the leading edge of the model.

   Figure 13: Density contour for the slotted passage aero-disk model with L/D ratio of 1.5

   o PRESSURE OF THE FLOW OVER ALL THE MOD- ELS:

   Generally, shock waves are formed when the model is placed in a flow with speed equal to or greater than the speed of the sound. The speed of the free stream flow used in the analysis is 1980 m/sec i.e., Mach 6. Pressure contours over any model describes about the location of formation of the shock waves on that model.

   Due to the blunt shape of the nose in the blunt body model, a detached strong bow shock is formed at the nose part of the model. But the detached distance is much less- er compared to the models with aero-disk. So, the area of re-circulation region formed at the nose part of the blunt body model is much lesser compared to all the other mod- els. Even then, there is a phenomenon of re-attachment of the shock waves to the models front surface as observed in the pressure contours. This is due to the presence of the aero-disk at the end of the arm attached to the model.

   Figure 15: Pressure contour for blunt body model

   Due to the presence of the slots like passages for this last model, the re- circulation zone is increased by its area due to which the re-compression waves intensity is reduced and is helpful in reducing the temperature at the nose part of the model. Thus, the aerodynamic heat reduction is achieved.

   Figure 16: Pressure contour for slotted passage aero-disk model with L/D ratio of 1.5

   Figure 17: Pressure contour for aero-disk model with disk radius o 20mm

   After comparing the results of different designs the one with disk radius of 20mm has less effect on it even at high pressure conditions.

   o Total Pressure of The Flow Over All The Models:

   Total pressure is the pressure experienced by the body when the flowing air is bought to a stop by the sur- face obstruction to the free stream flow. It can also be termed as the sum of both the static & dynamic pressure. This total pressure depends on the area of the surface of the

   body obstructing the free stream flow.

   The blunt body has a hemispherical surface at the nose part of the body. So, the total pressure on the surface is very high. The total pressure contour placed below de- scribes the total pressure on the blunt body model.

   Figure 18: Total pressure contour for blunt body model

   Due to presence of the slotted arm like passages in this last model, the total pressure is further reduced due to the air flowing from inside the slots into the recircula- tion region. The area of the low-pressure region gets en- larged.

   Figure 19: Total pressure contour for slotted passage aero-disk model with L/D ratio 1.5

   Figure 20: Total pressure contour for aero-disk model with disk radius of 20mm

   The total pressure readings indicate that due to in- crease in disk diameter the pressure acting on the head sur- face has increased when compared to slotted arm design.

   o STATIC TEMPERATURE OF THE FLOW OVER ALL THE MODELS:

   From the temperature contour, we can obtain the stat- ic temperature values of the flow over the surface of the body. This value can be helpful in determination of the suitable material that is needed to use in manufacturing the model. The temperature values on the surface of the whole body can be found by using probe & chart options availa- ble in the Results section of the CFX workbench. Blunt body model has a strong shock wave formed at its nose part, so the temperature at the nose part is higher since the re-circulation region is much lesser compared to the mod- els with aero-disk attachment.

   Whereas, in the case of the models with aero-disk at- tachment, due to the presence of the low-pressure re- circulation regions, the static temperature values are much less compared to the blunt body model.

   Figure 21: Temperature contour for blunt body model Temperature contour for blunt body model

   Figure 22: Temperature contour for slotted passage aero- disk model with L/D ratio of 1.5

   Figure 23: Temperature contour for aero-disk model with disk radius of 20mm

   • TOTAL TEMPERATURE OF THE FLOW OVER ALL THE MODELS:

     Since the shape of the nose part of the model is in blunt shape, more surface area is exposed to the free stream flow. This leads to increase in the total temperature at the nose part. If the total temperature at the nose portion in- creases to the value that cannot be sustained by the material used to make the model, there is a high risk of failure of the material and the model heated up and may even get vapor- ized.

     To keep away from the present circumstance, either excep- tionally heat safe material should be utilized or the model should have best streamlined plan. In any case, there no such material accessible now to oblige and oppose a high worth of absolute temperature. Thus, there could be no other choice than to pick streamlined planning to abstain from warming.

     Figure 24: Total temperature for blunt body model

     Figure 25: Total temperature contour for slotted passage aero-disk model with L/D ratio of 1.5

     From the above total temperature contours & plots, it clearly indicates that the total temperature at the nose por- tion of the model changes with respect to change in the length of the arm. And this total temperature value is much lesser in the model with a greater radius of disk compared to all the other models.

     Figure 26: Total temperature contour for aero-disk model with disk radius of 20mm

     The total temperature value on the leading edge of the model can be obtained using the probe option from the Results section in ANSYS CFX. These are the run of ANSYS CFX Solver that has finished and produced a solu-

     tion of momentum and mass, heat transfer, turbulence and wall& boundary scale.

     Figure 27: momentum and mass

     Figure 28: heat transfer

     Figure 29: turbulence

5. CONCLUSION & FUTURE RESEARCH

   • CONCLUSION:

     The CFD analysis for three different models as de- scribed in the earlier context of the project report, is per- formed, studied & results are explained successfully under shear stress turbulent (SST) model conditions using AN- SYS-CFX software. The operating Mach number is 6. In this study, we have found that in majority of the analysis done the design with bigger disk size about 20mm radius has higher efficiency in aerodynamic heat reduction, pres- sure reduction compared to all the other models. The pro- cesses done to analyze the models designed are

     • FLOW VISUALIZATION OF ALL THE MODELS DENSITY OF THE FLOW OVER ALL THE

       MODELS

     • PRESSURE OF THE FLOW OVER ALL THE MODELS

     • TOTAL PRESSURE OF THE FLOW OVER ALL THE MODELS

     • STATIC TEMPERATURE OF THE FLOW OVER ALL THE MODELS

     • TOTAL TEMPERATURE OF THE FLOW OVER ALL THE MODELS

   From all these analysis the results obtained by the de- sign with disk diameter of 40mm are compared to the re- sults obtained by the design of the slotted design. Having these results and base results of the blunt design of the body helps us understand and determine the apt design for the required results to be obtained.

   From our research study & CFD analysis, the aero- disk attachment model with larger disk size is the best & highly efficient model for aerodynamic heat reduction and can be used in designing hyper-sonic vehicles such as, re- entry capsules, hypersonic missiles, rockets, etc.

   Whereas the slotted model also has its perks and is helpful in some of the aspects like re-circulation and other analysis

   This concludes our research on the aerodynamic heat reduction on an aero-disk with disk radius of 20mm hyper- sonic model using computational analysis.

6. FUTURE RESEARCH:

   The research can be continued further on this slotted passage aero-disk model and model with lager disk size by varying different aspects such as the slots diameter, disk diameter, arm length and finding the loads acting on the arm. Loads acting on the arm helps understand the effect of slot and disk size by allowing us to know the buckling ca- pacity of the arm.

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