CN101404042A - Design calculation method for anti-icing blade - Google Patents

Abstract

The invention relates to a calculation method for designing a zero-level anti-icing blade of an engine compressor. The calculation method mainly comprises the following steps: establishing an blade internal thermal current chamber and independent flow units of an air introduction pipeline, then connecting all the independent flow units with the air introduction pipeline to form a flow network diagram, calculating the flow rate, the water impingement rate, the blade external heat transfer coefficient, the heat transfer coefficient of the blade internal thermal current chamber, and the blade heat balance, and finally analyzing the calculation results. The calculation method can quickly complete the establishment and modification of the blade internal thermal current chamber, the generation of the flow network diagram, the calculation of the flow rate, the heat transfer and the water impingement rate of the blade internal thermal current chamber, and the heat balance calculation and analysis, which shortens the design cycle and reduces the design cost.

Description

A kind of design and calculation method of anti-icing blade

Technical field:

The present invention relates to a kind of computing method of aero-gas turbine, be specifically related to a kind of design and calculation method of turboaxle motor pneumatic plant zero level anti-icing blade.

Background technology

Aero-gas turbine pneumatic plant zero level blade directly contacts with atmosphere, atmosphere enters pneumatic plant through pneumatic plant zero level blade, at arctic weather, the aqueous water that exists in the atmosphere impinges upon on the pneumatic plant zero level blade and freezes, freeze on the pneumatic plant zero level blade and can influence the operate as normal of engine, can damage engine when serious, influence flight safety.Normally introduce certain thermal current and prevent that pneumatic plant zero level blade from freezing.Blade interior hot gas runner, hot gas flow are to determine that by test the design cycle is long, the expense height.In order to shorten design cycle and expense, this just needs the anti-icing design and calculation method of a kind of blade, finishes the modification of the anti-ice structure of blade, the anti-icing designing and calculating of blade of performance evaluation.

Summary of the invention

It is short to the purpose of this invention is to provide a kind of design cycle, the anti-icing design and calculation method of the blade that expense is low.

Anti-icing blade design and calculation method of the present invention, this computing method step is as follows:

1, sets up blade interior thermal current chamber and bleed air line individual flow unit, whole individual flow unit and bleed air line are connected and composed flow network figure;

2, flow rate calculation

For arbitrary streaming node, air mass flow is calculated formula and is:

$\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{q}_{\mathrm{mij}}=0$

In the formula: q _MijThe algebraic value of the mass rate of-each branch of linking to each other with node i

3, the water impact rate is calculated

The water impact rate is the summation of blade inlet edge circle, leaf basin, blade back and trailing edge circle partial water impact rate, partial water impact rate calculating formula:

W″ _w，l＝ρ _w*V ₀*β，

$\mathrm{\β}=\frac{d{Y}_0}{\mathrm{ds}}$

In the formula: ρ _wDensity: V ₀Speed, partial water collision efficiency, ds infinitesimal area, dY ₀The water droplet spacing

4, the outer coefficient of heat transfer of blade calculates

The outer coefficient of heat transfer of blade comprises blade inlet edge, leaf basin, blade back and the local coefficient of heat transfer of trailing edge circle, and the computing formula of the blade inlet edge coefficient of heat transfer is:

$\mathrm{\α}=1.14\frac{\mathrm{\λ}}{D}{\mathrm{Re}}_D^{0.5}{\mathrm{Pr}}^{0.4}[1-{\left(\frac{\mathrm{\θ}}{90}\right)}^3]$

In the formula: the coefficient of heat conductivity of λ-air, D-blade inlet edge equivalent diameter,

Re _D-be the incoming flow air Reynolds number of characteristic dimension with D

Pr-air Prandtl number, θ-meter is from the angle in leading edge stationary point

The computing formula of leaf basin, blade back and the trailing edge circle coefficient of heat transfer is:

$\mathrm{\&alpha;}=n_c\frac{\mathrm{\&lambda;}}{S}{\mathrm{Re}}_{\mathrm{<figure-callout\; id="2"\; label="S\; n"\; filenames="A20081014359700091.png"\; state="\{\{state\}\}">S</figure-callout>}}^n{\mathrm{<figure-callout\; id="1"\; label="Pr\; n"\; filenames="A20081014359700091.png"\; state="\{\{state\}\}">Pr</figure-callout>}}^n$

In the formula: n _c=0.02--0.4, n ₁=0.05-0.7, n ₂=0.25-0.5

The coefficient of heat conductivity of λ-air, s-blade surface arc length

Re _s-be the incoming flow air Reynolds number of characteristic dimension with s, Pr-air Prandtl number

5, the coefficient of heat transfer in blade interior thermal current chamber calculates

The coefficient of heat transfer computing formula in blade interior hot-fluid chamber is:

$\mathrm{\&alpha;}=0.023\frac{\mathrm{\&lambda;}}{\mathrm{De}}{\mathrm{Re}}_{\mathrm{De}}^{0.8}{\mathrm{Pr}}^{0.4}$

In the formula: the coefficient of heat conductivity of λ-air, the equivalent diameter of De-circulation duct

Re _De-be the Reynolds number of characteristic length with De, Pr-air Prandtl number

6, blade heat Balance Calculation

Blade thermal equilibrium is blade surface convection heat transfer hot-fluid q ₁, surface water evaporative heat loss q ₂, boundary-layer friction heating hot-fluid q ₃, to collecting the heating hot-fluid q of water ₄, water droplet kinetic energy changes the heating hot-fluid q of coming ₅, the balance of blade inner chamber thermal current heating hot-fluid q, blade heat Balance Calculation formula is:

q＝q ₁+q ₂-q ₃+q ₄-q ₅

The computing formula of blade surface Temperature Distribution t is

t＝f(q ₁，q ₂，q ₃，q ₄，q ₅)

7, result of calculation analysis

The minimum temperature t of blade surface Temperature Distribution t _MinComputing formula be:

t _min＝∑t

t _MinGreater than design point value t ₀The time, blade interior thermal current chamber is reasonable in design.

Anti-icing blade design and calculation method of the present invention has following advantage: can finish the flowing of the foundation in blade interior thermal current chamber and modification, flow network map generalization, blade interior thermal current chamber, heat exchange and water impact rate fast and calculate and the heat Balance Calculation analysis, it is short to shorten the design cycle, has reduced design cost.

Description of drawings

Fig. 1 is blade interior thermal current chamber of the present invention and bleed air line structural representation

Fig. 2 is flow network figure of the present invention

Among the figure 1, air entraining pipe, 2, first chamber, 3, second chamber, the 4, the 3rd chamber, the 5, the 4th chamber, the 6, the 5th chamber, 7, blade inlet edge, 8, blade trailing edge.

Embodiment

Set up 5 blade interior thermal current chambeies and bleed air line 1 an individual flow unit, again first chamber 2, second chamber 2, the 3rd chamber 4, the 4th chamber 6, the 5th chamber 7 and air entraining pipe 1 are connected into flow network figure, thermal current enters each thermal current chamber by air entraining pipe 1 successively by the stream of flow network figure, and the thermal current chamber outlet by trailing edge 8 enters in the sprue again.

According to formula $\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{q}_{\mathrm{mij}}=0$

The flow that calculates the thermal current chamber is:

q ₁₀=2.85 Grams Per Second q ₁₇=5.86 Grams Per Second q ₁₈=7.24 Grams Per Seconds

q ₁₄=5.86 Grams Per Second q ₁₂=2.85 Grams Per Seconds

According to formula W " _{W, l}=ρ _w* V ₀* β calculates the water outlet impact rate:

The W=1.536 Grams Per Second

According to formula

$\mathrm{\&alpha;}=1.14\frac{\mathrm{\&lambda;}}{D}{\mathrm{Re}}_D^{0.5}{\mathrm{Pr}}^{0.4}[1-{\left(\frac{\mathrm{\&theta;}}{90}\right)}^3]$

$\mathrm{\&alpha;}=\mathrm{nc}\frac{\mathrm{\&lambda;}}{s}{\mathrm{<figure-callout\; id="1"\; label="Re\; s\; n"\; filenames="A20081014359700091.png"\; state="\{\{state\}\}">Re</figure-callout>}}_{sn}^1{\mathrm{<figure-callout\; id="2"\; label="Pr\; n"\; filenames="A20081014359700091.png"\; state="\{\{state\}\}">Pr</figure-callout>}}^n$ Calculate:

1500 watts/meter of the outer coefficients of heat transfer of blade inlet edge ²K

210 watts/meter of the outer coefficients of heat transfer of leaf basin ²K

225 watts/meter of the outer coefficients of heat transfer of blade back ²K

135 watts/meter of the trailing edge coefficients of heat transfer ²K

According to formula $\mathrm{\&alpha;}=0.023\frac{\mathrm{\&lambda;}}{\mathrm{De}}{\mathrm{Re}}_{\mathrm{De}}^{0.8}{\mathrm{Pr}}^{0.4}$ Calculate

The coefficient of heat transfer in blade interior thermal current chamber

According to formula q=q ₁+ q ₂-q ₃+ q ₄-q ₅, t=f (q ₁, q ₂, q ₃, q ₄, q ₅)

Calculate;

Blade surface Temperature Distribution t (280,290 ... 317K)

According to formula t _Min=∑ t

Calculate blade surface minimum temperature t _Min=280K, minimum temperature t _MinGreater than design point t ₀=273K, designed anti-icing blade meets design requirement.

Claims (1)

1, a kind of anti-icing blade design and calculation method is characterized in that:

A, set up blade interior thermal current chamber and bleed air line individual flow unit, whole individual flow unit and bleed air line are connected and composed flow network figure;

B, flow rate calculation

For arbitrary streaming node, air mass flow is calculated formula and is:

$\underset{j=1}{\overset{n}{\mathrm{\&Sigma;}}}{q}_{\mathrm{mij}}=0$

In the formula: q _Mij-the algebraic value of mass rate from the i flow unit to the j flow unit;

C, water impact rate are calculated

The water impact rate is the summation of blade inlet edge circle, leaf basin, blade back and trailing edge circle partial water impact rate, and the calculating formula of partial water impact rate is:

W″ _w，l＝ρ _w*V ₀*β

$\mathrm{\&beta;}=\frac{d{Y}_0}{\mathrm{ds}}$

In the formula: ρ _wDensity: V ₀Speed, partial water collision efficiency, ds infinitesimal area, dY ₀The water droplet spacing;

D, the outer coefficient of heat transfer of blade calculate

The outer coefficient of heat transfer of blade comprises blade inlet edge, leaf basin, blade back and the local coefficient of heat transfer of trailing edge circle, and the computing formula of blade inlet edge is:

$\mathrm{\&alpha;}=1.14\frac{\mathrm{\&lambda;}}{D}{\mathrm{Re}}_D^{0.5}{\mathrm{Pr}}^{0.4}[1-{\left(\frac{\mathrm{\&theta;}}{90}\right)}^3]$

In the formula: the coefficient of heat conductivity of λ-air, D-blade inlet edge equivalent diameter,

Re _D-be the incoming flow air Reynolds number of characteristic dimension with D

Pr-air Prandtl number θ-meter is from the angle in leading edge stationary point,

The computing formula of leaf basin, blade back and trailing edge circle is:

$\mathrm{\&alpha;}=n_c\frac{\mathrm{\&lambda;}}{S}{\mathrm{Re}}_S^{n_2}{\mathrm{Pr}}^{n_1}$

In the formula: n _c=0.02--0.4, n ₁=0.05-0.7, n ₂=0.25-0.5

The coefficient of heat conductivity of λ-air, s-blade surface arc length

Re _S-be the incoming flow air Reynolds number of characteristic dimension with s, Pr-air Prandtl number;

The coefficient of heat transfer in E, blade interior thermal current chamber calculates

According to formula

$\mathrm{\&alpha;}=0.023\frac{\mathrm{\&lambda;}}{\mathrm{De}}{\mathrm{Re}}_{\mathrm{De}}^{0.8}{\mathrm{Pr}}^{0.4}$

In the formula: the coefficient of heat conductivity of λ-air, the equivalent diameter of De-circulation duct

Re _De-be the Reynolds number of characteristic length with De, Pr-air Prandtl number;

F, blade heat Balance Calculation

According to heat Balance Calculation formula q=q ₁+ q ₂-q ₃+ q ₄-q ₅, calculate blade surface Temperature Distribution t;

G, result of calculation analysis

Blade surface Temperature Distribution t is by formula t _Min=∑ t calculates blade surface minimum temperature t _Min, t _MinGreater than design point value t ₀The time, blade interior thermal current chamber is reasonable in design.

Images