Aero brake

Abstract

Device is designed to change direction of inlet air (opposite to vehicle motion) from horizontal path to vertical path then to horizontal again through elbow duct and at same time it reduces cross section area of flow sharply. These paths increase drag force too much, that will act as aero brake to assist conventional brake to reduce braking distance during emergency with high stability. The device can be installed on front of vehicle or on back of vehicle where drag force will be generated by negative air pressure through suction process. Depth of the device is short, so it doesn't tack up much space inside vehicle. When driver does sharp steering at high speed, system can reduce automatically speed of vehicle till 70 km / hr at short time to maneuver vehicle safely and that help ESP to activate well. Also System can generate anti yaw torque to prevent under / over steering by passing air from one side for moment.

Description

[0001] Aero Brake

[0002] Technical Field

[0003] This device isfor automotive safety.

[0004] Background Art

[0005] Conventional Brake force depends on weight of vehicle * coefficient of friction between wheels and ground and it reduces on slippy road.

[0006] Technical Problem

[0007] This force isn’t sufficient to stop vehicle safely at high speed during emergency brake especially on slippy road.

[0008] Solution to Problem

[0009] Aero brake assists conventional brake to reduce braking distance during emergency with high stability.

[0010] Advantageous Effects of Invention

[0011] Aero brake will reduce crash on road too much consequentially number of death.

[0012] Disclosure of The Invention :

[0013] Detail of Invention

[0014] The system consists of a duct which changes direction of inlet air (opposite to vehicle motion) from horizontal path to vertical path then to horizontal again and at same time it reduces cross section area of flow sharply to generate high drag force and has strong doors to close inlet / exit area during normal running (as shown in figure 1A).

[0015] When driver presses brake pedal hardly, ABS activates and sends signal to open doors of device, so aero brake starts to activate (as shown in figure 2).

[0016] Generatived drag force mainly depends on speed of inlet air and size of inlet area.

[0017] When vehicle (air) speed increases, Generatived drag force increases too much. When inlet area increases, Generativeddrag force increases more (as shown in figure IB).

[0018] Using fan at inlet area can increase air flow rate and its pressure, consequentially increase drag force according to input power to fan from vehicle motor during emergency brake (as shown in figure 1C).

[0019] Also it can increase air flow rate and its pressure inside duct by injecting compressed air through jet nozzles as well as the normal inlet air (as shown in figure 2).

[0020] If diffuser is added after exit area, drag force will increase 25% more.

[0021] Depth of the device is short, so it doesn’t tack up much space inside vehicle.

[0022] The device can be installed on front of vehicle (as shown in figure 3 A) where drag force will be generated by positive air pressure which pushed to inlet area.

[0023] Also device can be installed on back of vehicle (as shown in figure 3B) where drag force will be generated by negative air pressure through suction process.

[0024] For compact vehicle, Double smaller pieces can be installed on both front sides (as shown in figure 4A) and / or inside rear bumper (as shown in figure 4B).

[0025] Double pieces aero brake can also generate anti yaw torque for stability.

[0026] Alsowhen driver does sharp steering athigh speed, system can reduce automaticallyspeedof vehicletill 70 km / hrat short time to maneuver vehicle safely and that help ESP to activate well.

[0027] Figure 5 shows how drag force increases too much when vehicle speed increases and increases more with air jet application (calculations for inlet area =35cm * 40 cm).

[0028] The study uses ANSYS fluent simulation for drag force, moment, mass flow rate calculations as well as pressure, velocity and pathline diagrams.

[0029] The following are five study sheets, for small inlet area, big inlet area, double pieces, device is installed on back of bus and device is installed on back of car (at vehicle speed = 35m / s): Sheetl

[0030] Atinlet air velocity = 35 m / s inlet area = 80cm * 35 cm (Figure 1 A) on front of vehicle = positive pressure (as Figure 3A)

[0031] Results:

[0032] Forces (n):

[0033] Fx = 21178.801 Fy = -759.65771 Fz = 0.51453329

[0034] Moments (n-m):

[0035] Mx = -0.97949887 My = 7.1960141 Mz = -3551.8612 (to get zero Mz ..keepFx axis on c.g. of vehicle and Fy = 0)

[0036] Mass Flow Rate (kg / s): inlet = 12.005 interior-enclosure= 232.91797

[0037] Outlet = -11.982337

[0038] Net = 0.022663327 kg / s

[0039] Figure 6 shows pressure, velocity and pathline inside the device when air enters at 35m / s.

[0040] Sheet!

[0041] Atinlet air velocity = 35 m / s inlet area = 80cm * 80 cm (Figure IB) on front of vehicle = positive pressure (as Figure 3 A)

[0042] Results:

[0043] Forces (n): Fx = 70340.013 Fy = 1864.9527 Fz = -10.896284

[0044] Moments (n-m):

[0045] Mx = 8.9208954 My = -9.7370056 Mz = -13037.443 (to get zero Mz ..keepFx axis on c.g. of vehicle and Fy = 0)

[0046] Mass Flow Rate (kg / s): inlet = 25.725 interior-enclosure = 28.167748

[0047] Outlet = -25.727843

[0048] Net = -0.0028427541 kg / s

[0049] Figure 7 shows pressure, velocity and pathline inside the device when air enters at 35m / s.

[0050] Sheet3

[0051] Atinlet air velocity = 35 m / s inlet area = 35cm * 40 cm (per piece of double) (Figure 4A) on front of vehicle = positive pressure (Figure 4A)

[0052] Results:

[0053] Forces (n):

[0054] Fx = 10891.686 Fy = 695.00976 Fz = 0.020516683

[0055] Moments (n-m):

[0056] Mx = -0.0066317476 My = 0.068903221Mz = -1073.7582 (to get zero Mz ..keepFx axis on c.g. of vehicle and Fy = 0)

[0057] Mass Flow Rate (kg / s): inlet = 6.1741906 interior-enclosure = 20.441178 Outlets -6.1855425

[0058] Net = -0.011351952 kg / s

[0059] Figure 8 shows pressure, velocity and pathline inside the device when air enters at 35m / s.

[0060] Sheet4

[0061] Atinlet air velocity = -35 m / s inlet area = 80cm * 80 cm (Figure IB) on back of vehicle = negative pressure (Figure 3B)

[0062] Results:

[0063] Forces (n):

[0064] Fx = -57465.973 Fy = 5484.4288 Fz = -24.028024 (bus can use inlet area

[0065] = 2.5m * Im for huge Fx)

[0066] Moments (n-m):

[0067] Mx = 7.100474 My = -86.564386 Mz = 1815.0741 (to get zero Mz ..keepFx axis on c.g. of vehicle and Fy = 0)

[0068] Mass Flow Rate (kg / s): inlet = -25.725 interior-enclosure = 156.98703

[0069] Outlet = 25.727843

[0070] Net = 0.0044572926 kg / s

[0071] Figure 9 shows pressure, velocity and pathline inside the device when air enters at -35m / s. Sheets

[0072] Atinlet air velocity = -35 m / s inlet area = 35cm * 150 cm (Figure 4B) on back of vehicle = negative pressure (Figure 4B)

[0073] Results:

[0074] Forces (n):

[0075] Fx = -40630.251 Fy = 4549.1935 Fz = -16.523708

[0076] Moments (n-m):

[0077] Mx = -4.5199732 My = -25.606334 Mz = -6448.8029 (to get zero Mz ..keepFx axis on c.g. of vehicle and Fy = 0)

[0078] Mass Flow Rate (kg / s): inlet = -22.510068 interior-enclosure = 192.9844

[0079] Outlet = 22.509789

[0080] Net = -0.00027878049

[0081] Figure 10 shows pressure, velocity and pathline inside the device when air enters at -35m / s.

[0082] Industrial Applicability

[0083] Manufacturing of device is applicable and volume of device is compact where it can find location inside vehicle to be assembled.

[0084] System is stable due to effecting on body directly and double pieces aero brake can generate anti yaw torque formore stability.

[0085] If rear camera detects closer vehicle, system can be deactivated until all vehicles on road equipped with aero brake system. Brief Description of Drawings

[0086] 1. Door

[0087] 2. Air jet

[0088] 3. Air valve

[0089] 4. Compressed air tank

[0090] 5. ABS

[0091] 6. Inlet air

[0092] 7. Exit air

[0093] P Pressure

[0094] V Velocity

[0095] L Pathlines

Claims

Claims

1. : Device changes direction of inlet air (opposite to vehicle motion) from horizontal path to vertical path then to horizontal again and at same time it reduces cross section area of flow sharply, where inlet area is too bigger than exit area to generate huge drag force acts as assistance brake (aero brake) during emergency in order to reduce braking distance especially at high speed or on slippy road.

2. : Aero brake system can generate drag force by assembling the device on front of vehicle through positive pressure or by assembling the device on back of vehicle through negative (suction) pressure.

3. : Using fan at inlet area can increase air flow rate and its pressure, consequentially increase drag force according to input power to fan from vehicle motor during emergency brake.

4. : It can increase air flow rate and its pressure inside device by injecting compressed air through jet nozzles as well as the normal inlet air consequentially increase drag force.

5. : If diffuser is added after exit area, drag force will increase 25% more.

6. : System can reduce automatically high speed of vehicle till 70 km / hr at short time when driver does sharp steering to maneuver vehicle safely and that help ESP to activate well.

7. : Double pieces aero brake system can generate anti yaw torque to prevent under / over steering by passing air from one side for moment.

Images