Design method of hedging flame jet pipe capable of forming uniform velocity field

Abstract

The invention discloses a design method of a hedging flame jet pipe capable of forming a uniform velocity field. The design method is applied to the field of basic combustion research and hedging flame experimental devices. The spray pipe is divided into a spray pipe diffusion section, a spray pipe transition section and a spray pipe contraction section from the airflow inlet to the airflow outlet; the method includes: determining a nozzle diffusion section and a nozzle transition section according to geometric parameters of a nozzle contraction section; constraining the contour of the nozzle contraction section to obtain a contour expression of the nozzle contraction section; calculating evaluation parameters of the nozzle contraction section according to the contour expression of the nozzle contraction section; judging whether the evaluation parameters of the nozzle contraction section meet requirements or not, and if yes, obtaining a nozzle contraction section model; and if not, returning to adjust the contour constraint on the nozzle contraction section until the requirement is met and a nozzle contraction section model is obtained. According to the method, uniform outlet velocity distribution is formed in the experiment area, and the thickness of a boundary layer is effectively reduced, so that the effectiveness of hedging flame experiment data is ensured.

Description

technical field [0001] The invention relates to the fields of basic combustion research and opposing flame experimental devices, in particular to a design and optimization method of an opposing flame nozzle capable of forming a uniform velocity field. Background technique [0002] Hedging flames can study diffusion, premixed and partially premixed combustion, and provide basic data and references for turbulent combustion in practical engineering fields. And the hedging flame model can be numerically simulated using the quasi-one-dimensional assumption, which greatly reduces the amount of calculation compared with high-dimensional simulation. Due to the above advantages, the simulation and experimental research of opposing flames has attracted extensive attention in the field of combustion. [0003] In the experimental study of opposing flames, the structure of the opposing nozzles is a key factor affecting the quality of the flow field. Inhomogeneous outlet velocity distri...

AI Technical Summary

Problems solved by technology

Inhomogeneous outlet velocity distribution and thicker boundary layer will have a greater impact on the experimental data of the impinging flame

At present, most of the experimental devices for opposed flames use straight nozzles or linear shrinkage nozzles, but such a nozzle structure is likely to lead to excessive thickness of the outlet boundary layer, flow separation, and transition from laminar flow to turbulent flow, so the validity of the experimental data cannot be guaranteed.

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