List of top Aerodynamics Questions

A single-stage axial compressor, with a 50 % degree of reaction, runs at a mean blade speed of 250 m/s. The overall pressure ratio developed is 1.3. Inlet pressure and temperature are 1 bar and 300 K, respectively. Axial velocity is 200 m/s. Specific heat at constant pressure, \( C_p = 1005 \, {J/kg/K} \) and specific heat ratio, \( \gamma = 1.4 \). The rotor blade angle at the outlet is __________ degrees (rounded off to two decimal places).

The mass flow rate in a supersonic wind tunnel is 2 kg/s when the stagnation pressure and stagnation temperature are 1 MPa and 800 K, respectively. If the stagnation pressure and stagnation temperature are changed to 3 MPa and 200 K, the mass flow rate in the tunnel changes to __________ kg/s (answer in integer).

A supersonic stream of an ideal gas at Mach number \( M_1 = 5 \) is turned by a ramp, as shown in the figure. The ramp angle is 20°. The pressure ratio is \( \frac{p_2}{p_1} = 7.125 \) and the specific heat ratio is \( \gamma = 1.4 \). The pressure coefficient on the ramp surface is ___________ (rounded off to two decimal places).

An aircraft is flying at an altitude of 4500 m above sea level, where the ambient pressure, temperature, and density are 57 kPa, 259 K, and 0.777 kg/m\(^3\), respectively. The speed of the aircraft \( V \) is 230 m/s. Gas constant \( R = 287 \, {J/kg/K} \), and specific heat ratio \( \gamma = 1.4 \). If the stagnation pressure is \( p_0 \), and static pressure is \( p \), the value of \[ \frac{p_0 - p}{\frac{1}{2} \rho V^2} \] is __________ (rounded off to two decimal places).

A lifting surface has a spanwise circulation distribution of \( \Gamma(\theta) = A \sin 3\theta \) (where \( A \neq 0 \)) over its span \( -\frac{b}{2} \leq y \leq \frac{b}{2} \), and \( y = -\frac{b}{2} \cos \theta \) is the spanwise coordinate. Furthermore, the downwash varies along the span as \( w(\theta) = V_\infty \left( \frac{3A \sin 3\theta}{\sin \theta} \right) \), where \( V_\infty \) is the freestream velocity. Which one of the following options represents the total lift \( L \) and induced drag \( D_i \)?

In a centrifugal compressor, the eye tip diameter is 10 cm. For a shaft rotational speed of 490 rotations per second, the tangential speed at the inducer tip is _________ m/s (rounded off to one decimal place).

The lift per unit span for a spinning circular cylinder in a potential flow is 6 N/m. The free-stream velocity is 30 m/s, and the density of air is 1.225 kg/m\(^3\). The circulation around the cylinder is __________ m\(^2\)/s (rounded off to two decimal places).

A single-stage axial compressor, with a 50 % degree of reaction, runs at a mean blade speed of 250 m/s. The overall pressure ratio developed is 1.3. Inlet pressure and temperature are 1 bar and 300 K, respectively. Axial velocity is 200 m/s. Specific heat at constant pressure, \( C_p = 1005 \, {J/kg/K} \) and specific heat ratio, \( \gamma = 1.4 \). The rotor blade angle at the outlet is \_\_\_\_\_\_\_ degrees (rounded off to two decimal places).
The mass flow rate in a supersonic wind tunnel is 2 kg/s when the stagnation pressure and stagnation temperature are 1 MPa and 800 K, respectively. If the stagnation pressure and stagnation temperature are changed to 3 MPa and 200 K, the mass flow rate in the tunnel changes to \_\_\_\_\_\_\_ kg/s (answer in integer).
An aircraft is flying at an altitude of 4500 m above sea level, where the ambient pressure, temperature, and density are 57 kPa, 259 K, and 0.777 kg/m\(^3\), respectively. The speed of the aircraft \( V \) is 230 m/s. Gas constant \( R = 287 \, {J/kg/K} \), and specific heat ratio \( \gamma = 1.4 \). If the stagnation pressure is \( p_0 \), and static pressure is \( p \), the value of \[ \frac{p_0 - p}{\frac{1}{2} \rho V^2} \] is \_\_\_\_\_\_\_\_ (rounded off to two decimal places).
A supersonic stream of an ideal gas at Mach number \( M_1 = 5 \) is turned by a ramp, as shown in the figure. The ramp angle is 20°. The pressure ratio is \( \frac{p_2}{p_1} = 7.125 \) and the specific heat ratio is \( \gamma = 1.4 \). The pressure coefficient on the ramp surface is \_\_\_\_\_\_\_\_ (rounded off to two decimal places).
A general aviation airplane is gliding with a speed \( V_g \) at minimum glide angle. Which of the following statements is/are true?
A lifting surface has a spanwise circulation distribution of \( \Gamma(\theta) = A \sin 3\theta \) (where \( A \neq 0 \)) over its span \( -\frac{b}{2} \leq y \leq \frac{b}{2} \), and \( y = -\frac{b}{2} \cos \theta \) is the spanwise coordinate. Furthermore, the downwash varies along the span as \( w(\theta) = V_\infty \left( \frac{3A \sin 3\theta}{\sin \theta} \right) \), where \( V_\infty \) is the freestream velocity. Which one of the following options represents the total lift \( L \) and induced drag \( D_i \)?
The lift per unit span for a spinning circular cylinder in a potential flow is 6 N/m. The free-stream velocity is 30 m/s, and the density of air is 1.225 kg/m\(^3\). The circulation around the cylinder is \_\_\_\_ m\(^2\)/s (rounded off to two decimal places).
In a centrifugal compressor, the eye tip diameter is 10 cm. For a shaft rotational speed of 490 rotations per second, the tangential speed at the inducer tip is \_\_\_ m/s (rounded off to one decimal place).
A single-stage axial compressor, with a 50 % degree of reaction, runs at a mean blade speed of 250 m/s. The overall pressure ratio developed is 1.3. Inlet pressure and temperature are 1 bar and 300 K, respectively. Axial velocity is 200 m/s. Specific heat at constant pressure, \( C_p = 1005 \, {J/kg/K} \) and specific heat ratio, \( \gamma = 1.4 \). The rotor blade angle at the outlet is \_\_\_\_\_\_\_ degrees (rounded off to two decimal places).
The mass flow rate in a supersonic wind tunnel is 2 kg/s when the stagnation pressure and stagnation temperature are 1 MPa and 800 K, respectively. If the stagnation pressure and stagnation temperature are changed to 3 MPa and 200 K, the mass flow rate in the tunnel changes to \_\_\_\_\_\_\_ kg/s (answer in integer).
A supersonic stream of an ideal gas at Mach number \( M_1 = 5 \) is turned by a ramp, as shown in the figure. The ramp angle is 20°. The pressure ratio is \( \frac{p_2}{p_1} = 7.125 \) and the specific heat ratio is \( \gamma = 1.4 \). The pressure coefficient on the ramp surface is \_\_\_\_\_\_\_\_ (rounded off to two decimal places).
An aircraft is flying at an altitude of 4500 m above sea level, where the ambient pressure, temperature, and density are 57 kPa, 259 K, and 0.777 kg/m\(^3\), respectively. The speed of the aircraft \( V \) is 230 m/s. Gas constant \( R = 287 \, {J/kg/K} \), and specific heat ratio \( \gamma = 1.4 \). If the stagnation pressure is \( p_0 \), and static pressure is \( p \), the value of \[ \frac{p_0 - p}{\frac{1}{2} \rho V^2} \] is \_\_\_\_\_\_\_\_ (rounded off to two decimal places).
A lifting surface has a spanwise circulation distribution of \( \Gamma(\theta) = A \sin 3\theta \) (where \( A \neq 0 \)) over its span \( -\frac{b}{2} \leq y \leq \frac{b}{2} \), and \( y = -\frac{b}{2} \cos \theta \) is the spanwise coordinate. Furthermore, the downwash varies along the span as \( w(\theta) = V_\infty \left( \frac{3A \sin 3\theta}{\sin \theta} \right) \), where \( V_\infty \) is the freestream velocity. Which one of the following options represents the total lift \( L \) and induced drag \( D_i \)?
A general aviation airplane is gliding with a speed \( V_g \) at minimum glide angle. Which of the following statements is/are true?
The lift per unit span for a spinning circular cylinder in a potential flow is 6 N/m. The free-stream velocity is 30 m/s, and the density of air is 1.225 kg/m\(^3\). The circulation around the cylinder is \_\_\_\_ m\(^2\)/s (rounded off to two decimal places).
In a centrifugal compressor, the eye tip diameter is 10 cm. For a shaft rotational speed of 490 rotations per second, the tangential speed at the inducer tip is \_\_\_ m/s (rounded off to one decimal place).
A single-stage axial compressor, with a 50 % degree of reaction, runs at a mean blade speed of 250 m/s. The overall pressure ratio developed is 1.3. Inlet pressure and temperature are 1 bar and 300 K, respectively. Axial velocity is 200 m/s. Specific heat at constant pressure, \( C_p = 1005 \, {J/kg/K} \) and specific heat ratio, \( \gamma = 1.4 \). The rotor blade angle at the outlet is \_\_\_\_\_\_\_ degrees (rounded off to two decimal places).
The mass flow rate in a supersonic wind tunnel is 2 kg/s when the stagnation pressure and stagnation temperature are 1 MPa and 800 K, respectively. If the stagnation pressure and stagnation temperature are changed to 3 MPa and 200 K, the mass flow rate in the tunnel changes to \_\_\_\_\_\_\_ kg/s (answer in integer).