Quasi-One-Dimensional Flow Modeling for Flight Environment Simulation System of Altitude Ground Test Facilities

Abstract

The Flight Environment Simulation System (FESS) at Altitude Ground Test Facilities (AGTF) is used to test aircraft engines. The FESS model is the basis of research and verification of advanced control algorithms. To further improve the steady and dynamic accuracy of the FESS model, a modeling method based on quasi-one-dimensional flow is proposed. Firstly, based on the unified inlet/outlet boundary specifications, the component models of test equipment, such as the quasi-one-dimensional flow model of pipe, the regulating valve model considering the heat transfer process, the multi-inlet and multi-outlet volume model reflecting the mixing characteristics of air flow, and the air source model and engine model, were established. Secondly, according to the real structure and working mechanism of the FESS, the above component models were used to build the numerical simulation model of the FESS. The simulation results showed that the relative deviation of mass flow and pressure were less than 4.4% and 0.9%, respectively, which verifies the correctness of the modeling method. In addition, the PI controller was designed for the FESS, and the simulation results show that the model is able to support controller development and verification.

PSO‐SMADRC for altitude test facility intake pressure environmental simulation system

“…Cavity model: The chamber can be modelled as a single-input, singleoutput cavity. By combining the gas state equation, internal energy equation, and thermodynamic equation based on the laws of thermodynamics, the pressure model of the cavity can be obtained as Equation ( 4) [10].…”

“…This section provides a brief description of the IEPSS. Based on this model, a simulation platform for the IEPSS is constructed, as detailed in references [2, 10].…”

“…The chamber can be modelled as a single‐input, single‐output cavity. By combining the gas state equation, internal energy equation, and thermodynamic equation based on the laws of thermodynamics, the pressure model of the cavity can be obtained as Equation () [10]. $$$$\begin{equation} \begin{aligned} dP/dt= & R[T-(h-RT)/({{c}_{p}}-R)]{\left({{Q}_{\text{in}}}-{{Q}_{\text{out}}} \right)}/{{V}_{t}}+ \\ & R{\left({{h}_{\text{in}}}{{Q}_{\text{in}}}-{{h}_{\text{out }}}{{Q}_{\text{out }}} \right)}/[{{V}_{t}}({{c}_{p}}-R)] \end{aligned} \end{equation}$$$$where $${{V}_{t}}$$ is the volume of the cavity, R is the gas constant, T , h , $${{\text{and }c}_{p}}$$ represent the temperature, the enthalpy, and the heat capacity in the cavity, respectively.…”

A Multi-Cavity Iterative Modeling Method for the Exhaust Systems of Altitude Ground Test Facilities

“…The calculation process of static pressure balance, including Equations ( 7)- (15), is shown in Figure 5. The unit enthalpy at Section 3 can be calculated with the energy shown in Equation ( 16).…”

“…Sosunov considered the thermal inertia of pipes and proposed an unsteady temperature calculation method [14]. In 2022, Liu et al started to focus on the axial dynamic performance in AGTFs and built a quasi-one-dimensional flow model of a pipe [15] because Sheeley et al proved that the accuracy of the lumped-parameter model is inadequate [16]. Moreover, robust control algorithms such as scheduled proportional-integral control [17], linear active disturbance rejection [18] and µ synthesis [19] are presented as a compromise to the inaccurate system model.…”