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Advances in Spacecraft Technologies Part 10

Tham khảo tài liệu 'advances in spacecraft technologies part 10', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 350 Advances in Spacecraft Technologies Fig. 30. Minimum Drag Coefficient Profile Front And Rear Directions For A Cone H D 1 DSMC Specularity 0 - 64.3 Degrees Off Of Cone Axis The average minimum maximum and range for the cone drag coefficient is displayed in Table 3 by model type. Notice once again that the average value of the DSMC model with a specularity of 25 is very close the average of the experimental data model. A value of 0 has proven not to be realistic as it does not correlate well with the other results. DSMC 0 DSMC 25 DSMC 50 Experiment Average 2.080749 1.980765 1.880782 1.9716522 Max 2.216739 2.620121 3.038154 2.842236 Min 1.993266 1.729126 1.241512 1.732459 Range 0.223473 0.890995 1.796642 1.109777 Table 3. Data Summary For Cone Drag Coefficients H D 1 Using 4 Model Variations 4. Drag coefficients for complex satellite shapes The modeling program ThreeD is designed to combine an unlimited number of plate elements to create more complex shapes. A more complex satellite designated CubeSat was created using some simple shapes and is shown in Figure 31. This satellite has a cubeshaped bus four solar array panels that are articulated at an angle of 60 degrees from one of the faces of the cube and a gravity gradient boom modeled with a tapered cylinder. The projected area for this satellite is shown in Figure 32. The drag coefficient profile is shown in Figure 33. Fig. 31. Example Of A Complex Satellite For Drag Coefficient Modeling Cubesat 351 Aerodynamic Disturbance Force and Torque Estimation For Spacecraft and Simple Shapes Using Finite Plate Elements - Part I Drag Coefficient Projected Area for CubeSat Z - Rotation Degrees X 0 X 10 - X 20 - -X 30 - -X 40 X 50 -t-X 60 X 70 X 80 X 90 Fig. 32. Projected Area For Cubesat Example Z - Rotation Degrees X 0 ---X 10 X 20 X 30 - -X 40 X 50 X 60 X 70 X 80 X 90 Fig. 33. Drag Profile For Cubesat Using ESM Plate Model 5. Conclusions This chapter has shown a method for determining the drag coefficient for simple .